Advanced Methods To Target and Eliminate Unlawful Robocalls, 13416-13425 [2025-04811]

Agencies

• FEDERAL COMMUNICATIONS COMMISSION

[Federal Register Volume 90, Number 55 (Monday, March 24, 2025)]
[Rules and Regulations]
[Pages 13416-13425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-04811]


=======================================================================
-----------------------------------------------------------------------

FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 64

[CG Docket No. 17-59; FCC 25-15; FR ID 285031]


Advanced Methods To Target and Eliminate Unlawful Robocalls

AGENCY: Federal Communications Commission.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: In this document, the Federal Communications Commission 
(Commission) modifies its existing call blocking rules. Specifically, 
the Commission requires all domestic voice service providers to block 
based on a reasonable do-not-originate (DNO) list. Second, it requires 
voice service providers to return Session Initiation Protocol (SIP) 
code 603+ when calls are blocked based on reasonable analytics.

DATES: Effective March 25, 2026, except for the amendment to 47 CFR 
64.1200(o) which are delayed indefinitely. The amendments to 47 CFR 
64.1200(o) will become effective following publication

[[Page 13417]]

of a document in the Federal Register announcing approval of the 
information collection and the relevant effective date.

FOR FURTHER INFORMATION CONTACT: Jerusha Burnett, Consumer Policy 
Division, Consumer and Governmental Affairs Bureau, email at 
[email protected] or by phone at (202) 418-0526. For information 
regarding the Paperwork Reduction Act (PRA) information collection 
requirements contained in the PRA, contact Cathy Williams, Office of 
Managing Director, at (202) 418-2918, or [email protected].

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Report 
and Order, in CG Docket No. 17-59, FCC 25-15, adopted on February 27, 
2025, and released on February 28, 2025. The full text of this document 
is available online at https://docs.fcc.gov/public/attachments/FCC-25-15A1.pdf.
    To request this document in accessible formats for people with 
disabilities (e.g., Braille, large print, electronic files, audio 
format) or to request reasonable accommodations (e.g., accessible 
format documents, sign language interpreters, CART), send an email to 
[email protected] or call the FCC's Consumer and Governmental Affairs 
Bureau at (202) 418-0530.

Final Paperwork Reduction Act of 1995 Analysis

    This document contains new or modified information collection 
requirements subject to the Paperwork Reduction Act of 1995 (PRA), 
Public Law 104-13. This document will be submitted to the Office of 
Management and Budget (OMB) for review under section 3507(d) of the 
PRA. OMB, the general public, and other Federal agencies will be 
invited to comment on the new or modified information collection 
requirements contained in this proceeding.

Congressional Review Act

    The Commission sent a copy of the Report and Order to Congress and 
the Government Accountability Office pursuant to the Congressional 
Review Act, see 5 U.S.C. 801(a)(1)(A).

Synopsis

    1. In this Report and Order, the Commission strengthens its call 
blocking and robocall mitigation rules in key areas. First, the 
Commission expands its requirement to block calls based on a reasonable 
do-not-originate (DNO) list to include all U.S.-based providers in the 
call path. The Commission next establishes Session Initiation Protocol 
(SIP) code 603+ as the exclusive code to notify callers when calls on 
internet Protocol (IP) networks are blocked based on reasonable 
analytics to better correct erroneous blocking.

Requiring All Providers To Block Using a Reasonable Do-Not-Originate 
List

    2. The Commission adopts its proposal to require all providers in 
the call path to block calls that are highly likely to be illegal based 
on a reasonable DNO list. Requiring all providers to block using a 
reasonable DNO list ensures that this type of blocking protects all 
voice customers. Even if some providers use more limited lists that are 
nonetheless reasonable, either out of concern that lawful calls may be 
blocked or because of technical limitations, consumers will be better 
protected because other providers in the call path may use more 
extensive lists, or even slightly different lists. The Commission 
therefore agrees with commenters that broadly support extension of the 
DNO blocking requirement to all voice service providers. The Commission 
makes this requirement effective 90 days after publication of a notice 
of Office of Management and Budget approval in the Federal Register.
    3. While the Commission agrees with USTelecom that many providers 
already block based on such lists, it disagrees with it that this makes 
a mandate unnecessary. Requiring more providers to block based on a DNO 
list will ensure that more consumers are protected from illegal calls. 
Further, the Commission is unpersuaded that any potential 
inefficiencies that stem from requiring all providers to block based on 
a reasonable DNO list outweigh the potential benefits. A provider may 
implement this requirement in whatever method makes sense for its 
network, so long as the list is applied to all calls that transit the 
provider's network. The Commission also declines to adopt a safe harbor 
for blocking based on a reasonable DNO list, as Cloud Communications 
Alliance suggests, because it is unclear what liability a provider 
would face for blocking based on a such a list and the Commission is 
unaware of any provider facing such liability since the Commission 
first authorized this blocking in 2017.
    4. Scope of the List. Consistent with the Commission's rule for 
gateway providers and messaging providers, the Commission does not 
mandate the use of a specific list, but allows providers to use any DNO 
list so long as the list is reasonable. The Commission similarly does 
not change the scope of numbers that may be included on a reasonable 
DNO list. This ensures that its rule for gateway providers is 
consistent with the Commission's rule for all other providers and 
ensures that the categories of numbers from which there is no valid 
reason for calls to originate can be included on the list. Such a list 
may include only invalid, unallocated, and unused numbers, as well as 
numbers for which the subscriber has requested blocking. The Commission 
clarifies that, to be considered reasonable, a list may include only 
the above-referenced categories of numbers and need not include all 
possible covered numbers. This is particularly true for unused numbers, 
which may be difficult for some providers to identify in some cases. 
The Commission may, however, deem unreasonable a list so limited in 
scope that it leaves out obvious numbers that could be included with 
little effort. The Commission finds that the current categories of 
numbers appropriately balance the certainty that calls are highly 
likely to be illegal with the need to protect consumers from those 
calls. The Commission therefore agrees with commenters that ask it not 
to change the scope of numbers that may be included on a reasonable DNO 
list.
    5. Consistent with the Commission's rule, it does not adopt a 
single uniform list or establish a minimum list. Providers must 
constantly update DNO lists, especially if they include unused numbers 
that could go into use at any time, and there is not currently a 
standardized way to ensure that these updates would happen in real time 
for all providers. While this is true of either a centralized list or a 
provider-maintained list, a provider-maintained list may, for example, 
include only unused numbers assigned to that provider and automate 
number drop-off upon putting the number into use--or simply leave off 
these numbers if they cannot reasonably do so. Additionally, as Neustar 
notes, some voice service providers may have ``limitations in the 
number of DNO numbers that they can use'' due to ``older or less 
capable networking equipment.'' A provider-selected list better 
accounts for this issue than a uniform list, and technical limitations 
provide a valid reason for some numbers to be excluded. The Commission 
also recognizes that providers know their own networks and may be 
better positioned to determine what types of numbers should be 
prioritized. By contrast, a central list would need to include rules 
prioritizing particular numbers across the U.S. network, which may not 
be the best

[[Page 13418]]

approach in all cases. The Commission therefore agrees with Neustar 
that granting flexibility to providers allows them ``to adapt or 
customize their DNO list based on their customer base, traffic profile, 
and other reasonable considerations. This will help those voice service 
providers maximize protections for their customers.''
    6. The Commission therefore disagrees with commenters who argue 
that it should adopt a uniform list or establish a minimum list, 
require a more comprehensive list, or ``set the criteria for inbound-
only numbers to be the same as for government inbound-only numbers.'' 
Because of the potential technological limitations discussed above, the 
Commission declines to mandate a more extensive list at this time. The 
Commission also maintains its previous approach, which allows providers 
to exercise discretion as to what numbers they include on their lists, 
so long as the list includes, at a minimum: (1) ``any inbound-only 
government numbers where the government entity has requested the number 
be included;'' and (2) ``private inbound-only numbers that have been 
used in imposter scams, when a request is made by the private entity 
assigned such a number.'' Providers may, of course, include inbound-
only numbers that have not been used in imposter scams if they are 
capable of doing so.
    7. Moreover, while Somos correctly notes that ``the more 
comprehensive the DNO list . . . the more spoofed calls that will be 
blocked before reaching the intended victim,'' the Commission finds 
that the burden of requiring all providers, including smaller 
providers, to use an expansive DNO list is unnecessary at this time. 
This is particularly true when all other providers in the call path 
must block. Some providers will use or already use these more expansive 
lists, and a single call will often pass through several networks on 
its path to the recipient. As a result, many consumers will be 
protected by these more comprehensive lists even when one provider in 
the call path uses a more restricted list. The Commission recommends 
that providers, when technically feasible, use a more comprehensive 
list to safeguard even more consumers.

SIP Code for Immediate Notification of Analytics-Based Blocking

    8. The Commission modifies its requirement for terminating 
providers to provide immediate notification to callers when calls are 
blocked based on reasonable analytics. The Commission now requires the 
exclusive use of SIP code 603+ for this purpose on IP networks. The 
Commissions directs providers that block based on reasonable analytics 
to return SIP code 603+. This will ensure that callers learn when and 
why their calls are blocked based on reasonable analytics, which in 
turn will allow these callers to access redress when blocking errors 
occur. The Commission clarifies that this requirement only applies when 
providers block calls based on analytics; the Commission does not 
require providers to provide immediate notification when blocking based 
on a DNO list, pursuant to Commission notification if not based on 
analytics, or at the request of a customer without the use of 
analytics. As required by the Commission's rules, the Commission 
directs all providers to perform necessary software upgrades to ensure 
the codes it requires for such notification are appropriately mapped. 
Providers must ensure that calls that transit over Time Division 
Multiplexing (TDM) and IP networks return an appropriate code when 
calls are blocked based on an analytics program, and the correct ISUP 
code for this purpose remains 21. The Commission further directs voice 
service providers to cease using the standard version of SIP code 603, 
or SIP codes 607 or 608, for this purpose.
    9. Adopting 603+ for Immediate Notification on IP Networks. The 
Commission previously indicated that the existing rule allowing 
providers to use one of several codes for immediate notification of 
blocking based on an analytics program--i.e., SIP code 603, 607, or 
608--was a temporary measure. The TRACED Act requires the Commission to 
ensure that callers receive ``transparency and effective redress'' when 
their calls are blocked by analytics, and a single uniform code is the 
best way to achieve this transparency. The Commission therefore agrees 
with commenters such as INCOMPAS and Cloud Communications Alliance that 
urge it to adopt a single, uniform code. The Commission similarly 
agrees that providers should adopt and implement a code quickly. The 
implementation of a single code has already been delayed and should not 
be delayed for longer than is absolutely necessary for implementation.
    10. The record demonstrates that SIP code 603+ will provide more 
information to providers more quickly than SIP code 608, and likely at 
lower cost to providers. While both SIP codes 603+ and 608 could 
ultimately provide the information callers need, commenters disagree as 
to whether SIP code 603+ or 608 is the best code for this purpose. 
Despite the contention by some commenters that some providers currently 
use SIP code 608, it appears a limited number of providers use it for a 
limited number of calls and without the jCard. In the SIP code 608 
specification, the jCard is an optional feature but it is necessary to 
provide information such as the identity of the blocking provider and 
redress information. As a result, current uses of SIP code 608 tell a 
caller that a call was blocked based on analytics but not which 
provider blocked the call or how to file a dispute. Therefore, while 
SIP code 608 provides callers with the basic information that a call is 
blocked, it provides minimal actionable information. USTelecom notes 
that currently very few providers have implemented SIP code 608, which 
means that, when a caller receives a 608, there is a limited list of 
providers that may have blocked the call; it further notes that broader 
deployment will make identifying the blocking provider significantly 
more difficult, especially in cases where SIP Code 608 may be used by 
non-terminating providers. Some commenters argue that implementing the 
jCard would take a significant amount of time--even years. By contrast, 
SIP code 603+ is not currently in use, but can provide the same 
information without the complexity of the jCard; furthermore, since it 
builds on an existing code, it appears to be substantially less 
technically complex to implement.
    11. SIP code 603+ builds on SIP code 603, which is already in use 
in the network and is different from it in a few key ways. First, 
instead of the status line reading ``Decline'' as in the standard SIP 
code 603, 603+ will read ``Network Blocked.'' This provides immediate, 
standardized information to originating providers and callers that the 
code is being used to indicate analytics-based blocking. Additionally, 
ATIS has standardized the reason header to define and require text 
fields that indicate blocking is based on analytics, as well as contact 
information for redress. This contains significantly more information 
than that provided by SIP code 608 without the use of the optional 
jCard, and at least comparable to what that code would provide if fully 
implemented with the jCard.
    12. Commenters are correct that SIP code 603 was not originally 
intended for use as a notification for blocking. Indeed, when it was 
originally established, analytics-based blocking as we currently know 
it did not exist. And the Commission agrees with commenters that it has 
characterized the use of SIP code 603 as a temporary measure to satisfy 
the TRACED Act requirement to provide transparency

[[Page 13419]]

and effective redress for erroneous analytics-based blocking. However, 
except where ISUP code 21 is translated into a standard SIP code 603 
and therefore cannot be distinguished as a 603+, SIP code 603+ is 
substantially different both in the status line and in mandatory text 
fields. These significant modifications, which make SIP code 603+ 
distinct from a standard SIP code 603, ensure that 603+ is appropriate 
for this use, even though the standard SIP code 603 would be 
inappropriate for long term use to indicate analytics-based blocking.
    13. The Commission disagrees with commenters who argue that SIP 
code 608 is the more appropriate code because it is more readily 
accessible and easier for callers to analyze. The Commission 
understands that caller equipment may need to be modified to look for 
the text in the status line, rather than simply the number of the code, 
and that system changes may need to be done to read the text fields 
that include redress information. The Commission is not convinced that 
this is a particularly challenging hurdle for callers to overcome, 
however. The status line that includes the numerical code, whether 603 
or 608, also includes the reason phrase (in the case of 603+, ``Network 
Blocked''). While software may not currently be configured to read this 
reason phrase, commenters do not make a clear case that this software 
cannot be reconfigured. Indeed, at least one group of caller commenters 
appears to believe that such reconfiguration is possible and 
specifically supports the use of SIP code 603+, citing the ``Network 
Blocked'' portion of the status line, among other factors, as evidence 
it will work for their needs. Additionally, implementation of SIP code 
603+ will make specific redress information available to callers, which 
should significantly reduce, if not eliminate, the current need for 
callers to invest significant time into investigation and outreach in 
order to initiate redress with the correct provider. Moreover, if SIP 
code 608 were implemented with the jCard to provide this information, 
callers would presumably also need to make modifications to read the 
information provided by the jCard. Therefore, use of either code would 
appear to require some investment by callers. The Commission therefore 
expects that most high-volume callers will choose to modify their 
equipment to recognize SIP code 603+ and have sufficient incentive to 
do so.
    14. As part of the Commission's requirement for voice service 
providers to return SIP code 603+, the Commission clarifies that all 
providers in the call path must transmit the appropriate code to the 
origination point of the call, including ensuring that SIP code 603+ 
maps appropriately to ISUP code 21. Similarly, any IP provider that 
receives SIP code 603+ must ensure it transmits the full header, 
including all mandatory text fields established in the standard.
    15. Implementation Deadline and Sunsetting SIP codes 603, 607, and 
608. The Commission requires providers to implement SIP code 603+ no 
later than 12 months from publication of this Order in the Federal 
Register. The Commission finds that a one-year implementation period 
appropriately balances the need for callers to receive greater 
transparency and the need for interoperability testing and other 
finalizing work by providers. Providers should have long been aware 
that the Commission would want them to quickly implement such a change, 
as the TRACED Act requires transparency and effective redress and the 
Commission has described the current option to use the standard version 
of SIP code 603 as a temporary measure.
    16. The Commission also directs providers to cease using SIP codes 
603, 607, and 608 when calls are blocked using analytics once they have 
implemented 603+ and in no instance later than 12 months from 
publication of this Order in the Federal Register. The Commission 
therefore disagrees with Cloud Communications Alliance and INCOMPAS, 
which urge us to continue to allow the use of 608 and to require 
implementation of the requirements in six months. First, continuing to 
allow SIP code 608 would cause further confusion and uncertainty by 
reducing incentives for both providers and callers to update their 
systems appropriately which undermines the Commission's goal of 
mandating a single code. Second, while AT&T may already have 
effectively implemented 603+ in much of its network, AT&T is a single 
large provider and other providers, such as those with different 
network architecture, may to need additional time. Similarly, AT&T's 
ability to implement 608 without the jCard within 12 months does not 
indicate that other providers will not reasonably require additional 
time. Additionally, SIP code 608 without the jCard offers much less 
information compared to SIP code 603+. However, when SIP code 608 
includes the jCard, it provides benefits similar to 603+, though it 
takes more time to implement. Therefore, it is more appropriate to use 
SIP code 608 with the jCard for comparison. While the Commission agrees 
that quicker implementation would be ideal and provide benefit to 
callers, it is concerned that doing so will be technically infeasible 
for quite a few providers, and therefore continue the cycle of delays 
and uncertainty.
    17. Providers may continue to use SIP code 603 where otherwise 
appropriate, but not for analytics-based blocking except when an 
intermediate or terminating providers receive ISUP code 21 and cannot 
reasonably determine whether SIP code 603 or 603+ is appropriate. SIP 
code 607 may be used for its intended purpose: to indicate that a call 
was blocked at the subscriber's direction without the use of analytics. 
Because the Commission requires immediate notification only when 
providers block based on reasonable analytics, it declines to mandate 
the use of SIP code 607. The Commission therefore disagrees with the 
commenter that urges it to require use of SIP code 607. While this 
information may be valuable to some callers, comments in previous 
proceedings indicate that there may be privacy concerns with its use. 
At this time, the Commission finds that these concerns outweigh the 
potential benefits and therefore decline to mandate the use of SIP code 
607.
    18. Additional Protections for Lawful Callers. Because the 
Commission does not adopt any requirements for blocking based on 
reasonable analytics and the blocking notification rules it adopts 
today are expansions of its existing rules, rather than wholly new 
requirements, it declines to adopt any additional protections for 
lawful callers at this time. The record does not suggest that the 
Commission's current protections will be insufficient to protect lawful 
callers after these particular incremental expansions take effect. 
Moreover, and as discussed previously, the Commission believes that the 
deployment of SIP code 603+ will provide significant benefit to callers 
that, when paired with the Commission's existing protections, are 
sufficient to protect the interests of callers.

Status of Rich Call Data or Other Caller Name Tools

    19. The Commission declines to require the display of caller name 
information when a provider chooses to display an indication that 
caller ID has been authenticated. Although the Commission does not 
adopt such a mandate, it urges providers to continue to develop next-
generation tools, such as Rich Call Data (RCD) and branded calling 
solutions, to ensure that consumers receive this information and 
welcome any updates industry has on its progress. The Commission notes 
that

[[Page 13420]]

it may consider a mandate in the future, particularly if the timely 
deployment of such valuable tools does not occur without Commission 
intervention. The record indicates both that CNAM databases are 
insufficient to provide a consumer with reliable information, and that 
a mandate requiring the use of other, newer, technologies is premature. 
Furthermore, the Commission agrees with consumer groups that the ``use 
of rented [Direct Inward Dialing numbers] just for the purpose of 
allowing callers to pretend to be someone other than themselves for the 
express purpose of evading blocking and labeling efforts'' is a concern 
that merits caution. Solutions that can provide secure end-to-end 
authentication and verification information can help restore trust in 
the ecosystem and enhance consumer welfare.
    20. Though the Commission declines to adopt a mandate at this time, 
it nonetheless believes that displaying caller name or other enhanced 
call information, once a reliable solution is available, will provide 
significant benefit to consumers, particularly when combined with an 
indication that caller ID has been authenticated. The Commission 
therefore strongly encourages industry to develop and standardize tools 
to ensure that this information is provided to consumers without 
additional charge to the call recipient. The Commission is concerned 
that, absent this information, an indication that caller ID has been 
authenticated provides little actionable information to consumers and 
may provide consumers with a false sense of security. The Commission 
intends to continue monitoring developments in this area in order to 
take action as appropriate in the future.

Legal Authority

    21. The Commission's legal authority for the rules it adopts today 
stems from sections 201(b), 202(a), and 251(e) of the Communications 
Act of 1934, as amended (the Act), as well as from the Truth in Caller 
ID Act, and the TRACED Act. These sections have formed the basis for 
much of the Commission's work to combat illegal calls. In particular, 
sections 201(b) and 202(a) grant the Commission broad authority to 
adopt rules governing just and reasonable practices of common carriers.
    22. The Commission's authority under section 251(e)(1) provides 
independent jurisdiction to prevent abuse of U.S. North American 
Numbering Plan (NANP) resources. This is particularly relevant to the 
rules the Commission adopts today that require blocking based on a 
reasonable DNO list, where there is no legitimate reason for the caller 
to use the number. Similarly, the Truth in Caller ID Act grants the 
Commission authority to prescribe rules to make unlawful the spoofing 
of caller ID information with the intent to defraud, cause harm, or 
wrongfully obtain something of value, and provides us authority to 
require blocking based on a reasonable DNO list where the number has 
clearly been spoofed.
    23. Section 10(b) of the TRACED Act directs the Commission to 
ensure that providers are transparent about blocking and give both 
consumers and callers effective redress for erroneous blocking. It 
provides authority for the Commission's designation of SIP code 603+ as 
the appropriate code for immediate notification of callers when calls 
are blocked based on reasonable analytics. The Commission adopted its 
original immediate notification requirement based on the authority of 
that section. The Commission now simply modify that requirement to 
ensure that callers receive greater transparency.

Cost-Benefit Analysis

    24. The record supports the Commission's conclusion that the 
actions it takes now to strengthen its rules will yield benefits to 
consumers that exceed the costs of their implementation. The Commission 
previously estimated that illegal and unwanted calls cost consumers 
$13.5 billion annually. Even if the actions the Commission takes now to 
strengthen its rules eliminate only a small fraction of these unwanted 
and fraudulent calls, the benefits will be substantial and will 
outweigh the costs.
    25. Benefits. Extending blocking to all voice service providers in 
the call path based on a reasonable DNO list will increase the 
proportion of unwanted and illegal calls that are successfully blocked. 
The collective effect of each provider in the call path using its own 
risk-based DNO list will be to better filter illegal and unwanted calls 
by blocking illegal calls that elude one provider's different DNO list. 
If the effect is to eliminate a small share of unwanted and illegal 
calls, consumers would save millions annually in avoided fraud, 
aggravation, inconvenience, and mistrust.
    26. Costs. While the record lacks specific cost data and related 
analysis, the Commission believes that the increase in providers' costs 
to avoid the risk of originating illegal calls will be modest. First, 
the DNO list blocking requirement of this Report and Order merely 
extends the existing requirement of previous orders. In the May 2023 
Call Blocking Order and Further Notice, the Commission reaffirmed that 
``voice service providers are responsible for the calls they originate, 
carry, or transmit.'' In this Report and Order, the Commission requires 
all voice service providers to block calls based upon a reasonable DNO 
list which is a modest extension of the responsibility for all calls on 
a network.
    27. Additionally, requiring providers to use SIP code 603+ for 
immediate notification to callers of analytics-based blocking is less 
technically complex than other potential solutions, and thus likely 
minimizes the costs of implementation for providers. SIP code 603+ 
builds on an existing code and thus requires less development than 
adoption of a new release code. In addition, voice service providers 
have 12 months after the publication of this Report and Order in the 
Federal Register to implement this change. Further, implementation of 
SIP code 603+ will make specific redress information available to 
callers, which should significantly reduce, if not eliminate, the 
current need for callers to invest significant time into investigation 
and outreach to initiate redress with the correct provider.
    28. Although the record is sparse, the new requirements in this 
Report and Order to reduce illegal calls can likely be implemented at a 
relatively modest cost. Given that unwanted and illegal calls reduce 
public welfare by billions of dollars annually, even a small percentage 
reduction in those will generate benefits that exceed the costs of the 
new rules.

Final Regulatory Flexibility Analysis

    29. As required by the Regulatory Flexibility Act of 1980 (RFA), as 
amended, an Initial Regulatory Flexibility Analysis (IRFA) was 
incorporated in the Advanced Methods to Target and Eliminate Unlawful 
Robocalls, Call Authentication Trust Anchor, Eighth Further Notice 
(Call Blocking FNPRM) released in May 2023. The Federal Communications 
Commission (Commission) sought written public comment on the proposals 
in the Call Blocking FNPRM, including comment on the IRFA. No comments 
were filed addressing the IRFA. This Final Regulatory Flexibility 
Analysis (FRFA) conforms to the RFA.

Need for, and Objectives of, the Order

    30. The Report and Order continues the Commission's ongoing efforts 
to stop the growing tide of illegal calls by building on its existing 
rules. The Commission has taken significant action

[[Page 13421]]

to combat this problem, and this Report and Order adopts several rules 
to continue this work. First, the Report and Order expands the existing 
requirements to block calls based on a reasonable do-not-originate 
(DNO) list. Additionally, it increases transparency for callers by 
mandating a single Session Initiation Protocol (SIP) code be used when 
calls are blocked based on reasonable analytic. The Commission's 
adoption of these requirements in the Report and Order strengthens its 
call blocking and robocall mitigation rules to provide enhanced 
protection for consumers.

Summary of Significant Issues Raised by Public Comments in Response to 
the IRFA

    31. Although the Commission did not receive comments specifically 
addressing the IRFA in the Call Blocking FNPRM, the Commission did 
receive comments addressing the burdens on small providers. Commenters 
expressed concerns regarding burdens associated with additional 
blocking requirements. With regard to the Commission's proposed 
requirement for all providers in the call path to block calls that are 
highly likely to be illegal based on a reasonable DNO list, commenters 
advocated for call blocking on a reasonable DNO list, no change to the 
scope of numbers included on a reasonable DNO list, a safe harbor from 
liability for providers based on the use of a reasonable DNO list. 
Further, commenters opined on the appropriate SIP code for immediate 
notification requirements and mandatory call-blocking based on 
reasonable analytics. Additionally, commenters raised concerns about 
short implementation times, and asked for additional time for smaller 
providers. The Commission carefully considered these concerns, and 
discusses steps taken to address them in section F of this FRFA. The 
Commission further considered the potential impact of the rules 
proposed in the IRFA on small entities, and took steps where 
appropriate and feasible, to reduce the compliance and economic burden 
for small entities.

Response to Comments by the Chief Counsel for Advocacy of the Small 
Business Administration

    32. Pursuant to the Small Business Jobs Act of 2010, which amended 
the RFA, the Commission is required to respond to any comments filed by 
the Chief Counsel for Advocacy of the Small Business Administration 
(SBA), and to provide a detailed statement of any change made to the 
proposed rules as a result of those comments. The Chief Counsel did not 
file any comments in response to the proposed rules in this proceeding.

Description and Estimate of the Number of Small Entities to Which Rules 
Will Apply

    33. The RFA directs agencies to provide a description of and, where 
feasible, an estimate of the number of small entities that may be 
affected by the rules and policies adopted herein. The RFA generally 
defines the term ``small entity'' as having the same meaning as the 
terms ``small business,'' ``small organization,'' and ``small 
governmental jurisdiction.'' In addition, the term ``small business'' 
has the same meaning as the term ``small business concern'' under the 
Small Business Act. A ``small business concern'' is one which: (1) is 
independently owned and operated; (2) is not dominant in its field of 
operation; and (3) satisfies any additional criteria established by the 
SBA.
    34. Small Businesses, Small Organizations, Small Governmental 
Jurisdictions. The Commission's actions, over time, may affect small 
entities that are not easily categorized at present. The Commission 
therefore describes, at the outset, three broad groups of small 
entities that could be directly affected herein. First, while there are 
industry specific size standards for small businesses that are used in 
the regulatory flexibility analysis, according to data from the Small 
Business Administration's (SBA) Office of Advocacy, in general a small 
business is an independent business having fewer than 500 employees. 
These types of small businesses represent 99.9% of all businesses in 
the United States, which translates to 33.2 million businesses.
    35. Next, the type of small entity described as a ``small 
organization'' is generally ``any not-for-profit enterprise which is 
independently owned and operated and is not dominant in its field.'' 
The Internal Revenue Service (IRS) uses a revenue benchmark of $50,000 
or less to delineate its annual electronic filing requirements for 
small exempt organizations. Nationwide, for tax year 2022, there were 
approximately 530,109 small exempt organizations in the U.S. reporting 
revenues of $50,000 or less according to the registration and tax data 
for exempt organizations available from the IRS.
    36. Finally, the small entity described as a ``small governmental 
jurisdiction'' is defined generally as ``governments of cities, 
counties, towns, townships, villages, school districts, or special 
districts, with a population of less than fifty thousand.'' U.S. Census 
Bureau data from the 2022 Census of Governments indicate there were 
90,837 local governmental jurisdictions consisting of general purpose 
governments and special purpose governments in the United States. Of 
this number, there were 36,845 general purpose governments (county, 
municipal, and town or township) with populations of less than 50,000 
and 11,879 special purpose governments (independent school districts) 
with enrollment populations of less than 50,000. Accordingly, based on 
the 2022 U.S. Census of Governments data, the Commission estimates that 
at least 48,724 entities fall into the category of ``small governmental 
jurisdictions.''

Wireline Carriers

    37. Wired Telecommunications Carriers. The U.S. Census Bureau 
defines this industry as establishments primarily engaged in operating 
and/or providing access to transmission facilities and infrastructure 
that they own and/or lease for the transmission of voice, data, text, 
sound, and video using wired communications networks. Transmission 
facilities may be based on a single technology or a combination of 
technologies. Establishments in this industry use the wired 
telecommunications network facilities that they operate to provide a 
variety of services, such as wired telephony services, including VoIP 
services, wired (cable) audio and video programming distribution, and 
wired broadband internet services. By exception, establishments 
providing satellite television distribution services using facilities 
and infrastructure that they operate are included in this industry. 
Wired Telecommunications Carriers are also referred to as wireline 
carriers or fixed local service providers.
    38. The SBA small business size standard for Wired 
Telecommunications Carriers classifies firms having 1,500 or fewer 
employees as small. U.S. Census Bureau data for 2017 show that there 
were 3,054 firms that operated in this industry for the entire year. Of 
this number, 2,964 firms operated with fewer than 250 employees. 
Additionally, based on Commission data in the 2022 Universal Service 
Monitoring Report, as of December 31, 2021, there were 4,590 providers 
that reported they were engaged in the provision of fixed local 
services. Of these providers, the Commission estimates that 4,146 
providers have 1,500 or fewer employees. Consequently, using the SBA's 
small business size standard, most of these providers can be considered 
small entities.

[[Page 13422]]

    39. Local Exchange Carriers (LECs). Neither the Commission nor the 
SBA has developed a size standard for small businesses specifically 
applicable to LECs. Providers of these services include both incumbent 
and competitive local exchange service providers. Wired 
Telecommunications Carriers is the closest industry with an SBA small 
business size standard. Wired Telecommunications Carriers are also 
referred to as wireline carriers or fixed local service providers. The 
SBA small business size standard for Wired Telecommunications Carriers 
classifies firms having 1,500 or fewer employees as small. U.S. Census 
Bureau data for 2017 show that there were 3,054 firms that operated in 
this industry for the entire year. Of this number, 2,964 firms operated 
with fewer than 250 employees. Additionally, based on Commission data 
in the 2022 Universal Service Monitoring Report, as of December 31, 
2021, there were 4,590 providers that reported they were fixed local 
exchange service providers. Of these providers, the Commission 
estimates that 4,146 providers have 1,500 or fewer employees. 
Consequently, using the SBA's small business size standard, most of 
these providers can be considered small entities.
    40. Incumbent Local Exchange Carriers (Incumbent LECs). Neither the 
Commission nor the SBA have developed a small business size standard 
specifically for incumbent local exchange carriers. Wired 
Telecommunications Carriers is the closest industry with an SBA small 
business size standard. The SBA small business size standard for Wired 
Telecommunications Carriers classifies firms having 1,500 or fewer 
employees as small. U.S. Census Bureau data for 2017 show that there 
were 3,054 firms in this industry that operated for the entire year. Of 
this number, 2,964 firms operated with fewer than 250 employees. 
Additionally, based on Commission data in the 2022 Universal Service 
Monitoring Report, as of December 31, 2021, there were 1,212 providers 
that reported they were incumbent local exchange service providers. Of 
these providers, the Commission estimates that 916 providers have 1,500 
or fewer employees. Consequently, using the SBA's small business size 
standard, the Commission estimates that the majority of incumbent local 
exchange carriers can be considered small entities.
    41. Competitive Local Exchange Carriers (LECs). Neither the 
Commission nor the SBA has developed a size standard for small 
businesses specifically applicable to competitive LECs. Providers of 
these services include several types of competitive local exchange 
service providers. Wired Telecommunications Carriers is the closest 
industry with a SBA small business size standard. The SBA small 
business size standard for Wired Telecommunications Carriers classifies 
firms having 1,500 or fewer employees as small. U.S. Census Bureau data 
for 2017 show that there were 3,054 firms that operated in this 
industry for the entire year. Of this number, 2,964 firms operated with 
fewer than 250 employees. Additionally, based on Commission data in the 
2022 Universal Service Monitoring Report, as of December 31, 2021, 
there were 3,378 providers that reported they were competitive local 
service providers. Of these providers, the Commission estimates that 
3,230 providers have 1,500 or fewer employees. Consequently, using the 
SBA's small business size standard, most of these providers can be 
considered small entities.
    42. Interexchange Carriers (IXCs). Neither the Commission nor the 
SBA have developed a small business size standard specifically for 
IXCs. Wired Telecommunications Carriers is the closest industry with a 
SBA small business size standard. The SBA small business size standard 
for Wired Telecommunications Carriers classifies firms having 1,500 or 
fewer employees as small. U.S. Census Bureau data for 2017 show that 
there were 3,054 firms that operated in this industry for the entire 
year. Of this number, 2,964 firms operated with fewer than 250 
employees. Additionally, based on Commission data in the 2022 Universal 
Service Monitoring Report, as of December 31, 2021, there were 127 
providers that reported they were engaged in the provision of 
interexchange services. Of these providers, the Commission estimates 
that 109 providers have 1,500 or fewer employees. Consequently, using 
the SBA's small business size standard, the Commission estimates that 
the majority of providers in this industry can be considered small 
entities.
    43. Cable System Operators (Telecom Act Standard). The 
Communications Act of 1934, as amended, contains a size standard for a 
``small cable operator,'' which is ``a cable operator that, directly or 
through an affiliate, serves in the aggregate fewer than one percent of 
all subscribers in the United States and is not affiliated with any 
entity or entities whose gross annual revenues in the aggregate exceed 
$250,000,000.'' For purposes of the Telecom Act Standard, the 
Commission determined that a cable system operator that serves fewer 
than 498,000 subscribers, either directly or through affiliates, will 
meet the definition of a small cable operator. Based on industry data, 
only six cable system operators have more than 498,000 subscribers. 
Accordingly, the Commission estimates that the majority of cable system 
operators are small under this size standard. The Commission notes 
however, that the Commission neither requests nor collects information 
on whether cable system operators are affiliated with entities whose 
gross annual revenues exceed $250 million. Therefore, the Commission is 
unable at this time to estimate with greater precision the number of 
cable system operators that would qualify as small cable operators 
under the definition in the Communications Act.
    44. Other Toll Carriers. Neither the Commission nor the SBA has 
developed a definition for small businesses specifically applicable to 
Other Toll Carriers. This category includes toll carriers that do not 
fall within the categories of interexchange carriers, operator service 
providers, prepaid calling card providers, satellite service carriers, 
or toll resellers. Wired Telecommunications Carriers is the closest 
industry with a SBA small business size standard. The SBA small 
business size standard for Wired Telecommunications Carriers classifies 
firms having 1,500 or fewer employees as small. U.S. Census Bureau data 
for 2017 show that there were 3,054 firms in this industry that 
operated for the entire year. Of this number, 2,964 firms operated with 
fewer than 250 employees. Additionally, based on Commission data in the 
2022 Universal Service Monitoring Report, as of December 31, 2021, 
there were 90 providers that reported they were engaged in the 
provision of other toll services. Of these providers, the Commission 
estimates that 87 providers have 1,500 or fewer employees. 
Consequently, using the SBA's small business size standard, most of 
these providers can be considered small entities.

Wireless Carriers

    45. Wireless Telecommunications Carriers (except Satellite). This 
industry comprises establishments engaged in operating and maintaining 
switching and transmission facilities to provide communications via the 
airwaves. Establishments in this industry have spectrum licenses and 
provide services using that spectrum, such as cellular services, paging 
services, wireless

[[Page 13423]]

internet access, and wireless video services. The SBA size standard for 
this industry classifies a business as small if it has 1,500 or fewer 
employees. U.S. Census Bureau data for 2017 show that there were 2,893 
firms in this industry that operated for the entire year. Of that 
number, 2,837 firms employed fewer than 250 employees. Additionally, 
based on Commission data in the 2022 Universal Service Monitoring 
Report, as of December 31, 2021, there were 594 providers that reported 
they were engaged in the provision of wireless services. Of these 
providers, the Commission estimates that 511 providers have 1,500 or 
fewer employees. Consequently, using the SBA's small business size 
standard, most of these providers can be considered small entities.
    46. Satellite Telecommunications. This industry comprises firms 
``primarily engaged in providing telecommunications services to other 
establishments in the telecommunications and broadcasting industries by 
forwarding and receiving communications signals via a system of 
satellites or reselling satellite telecommunications.'' Satellite 
telecommunications service providers include satellite and earth 
station operators. The SBA small business size standard for this 
industry classifies a business with $44 million or less in annual 
receipts as small. U.S. Census Bureau data for 2017 show that 275 firms 
in this industry operated for the entire year. Of this number, 242 
firms had revenue of less than $25 million. Additionally, based on 
Commission data in the 2022 Universal Service Monitoring Report, as of 
December 31, 2021, there were 65 providers that reported they were 
engaged in the provision of satellite telecommunications services. Of 
these providers, the Commission estimates that approximately 42 
providers have 1,500 or fewer employees. Consequently, using the SBA's 
small business size standard, a little more than half of these 
providers can be considered small entities.

Resellers

    47. Local Resellers. Neither the Commission nor the SBA have 
developed a small business size standard specifically for Local 
Resellers. Telecommunications Resellers is the closest industry with a 
SBA small business size standard. The Telecommunications Resellers 
industry comprises establishments engaged in purchasing access and 
network capacity from owners and operators of telecommunications 
networks and reselling wired and wireless telecommunications services 
(except satellite) to businesses and households. Establishments in this 
industry resell telecommunications; they do not operate transmission 
facilities and infrastructure. Mobile virtual network operators (MVNOs) 
are included in this industry. The SBA small business size standard for 
Telecommunications Resellers classifies a business as small if it has 
1,500 or fewer employees. U.S. Census Bureau data for 2017 show that 
1,386 firms in this industry provided resale services for the entire 
year. Of that number, 1,375 firms operated with fewer than 250 
employees. Additionally, based on Commission data in the 2022 Universal 
Service Monitoring Report, as of December 31, 2021, there were 207 
providers that reported they were engaged in the provision of local 
resale services. Of these providers, the Commission estimates that 202 
providers have 1,500 or fewer employees. Consequently, using the SBA's 
small business size standard, most of these providers can be considered 
small entities.
    48. Toll Resellers. Neither the Commission nor the SBA have 
developed a small business size standard specifically for Toll 
Resellers. Telecommunications Resellers is the closest industry with a 
SBA small business size standard. The Telecommunications Resellers 
industry comprises establishments engaged in purchasing access and 
network capacity from owners and operators of telecommunications 
networks and reselling wired and wireless telecommunications services 
(except satellite) to businesses and households. Establishments in this 
industry resell telecommunications; they do not operate transmission 
facilities and infrastructure. Mobile virtual network operators (MVNOs) 
are included in this industry. The SBA small business size standard for 
Telecommunications Resellers classifies a business as small if it has 
1,500 or fewer employees. U.S. Census Bureau data for 2017 show that 
1,386 firms in this industry provided resale services for the entire 
year. Of that number, 1,375 firms operated with fewer than 250 
employees. Additionally, based on Commission data in the 2022 Universal 
Service Monitoring Report, as of December 31, 2021, there were 457 
providers that reported they were engaged in the provision of toll 
services. Of these providers, the Commission estimates that 438 
providers have 1,500 or fewer employees. Consequently, using the SBA's 
small business size standard, most of these providers can be considered 
small entities.
    49. Prepaid Calling Card Providers. Neither the Commission nor the 
SBA has developed a small business size standard specifically for 
prepaid calling card providers. Telecommunications Resellers is the 
closest industry with a SBA small business size standard. The 
Telecommunications Resellers industry comprises establishments engaged 
in purchasing access and network capacity from owners and operators of 
telecommunications networks and reselling wired and wireless 
telecommunications services (except satellite) to businesses and 
households. Establishments in this industry resell telecommunications; 
they do not operate transmission facilities and infrastructure. Mobile 
virtual network operators (MVNOs) are included in this industry. The 
SBA small business size standard for Telecommunications Resellers 
classifies a business as small if it has 1,500 or fewer employees. U.S. 
Census Bureau data for 2017 show that 1,386 firms in this industry 
provided resale services for the entire year. Of that number, 1,375 
firms operated with fewer than 250 employees. Additionally, based on 
Commission data in the 2022 Universal Service Monitoring Report, as of 
December 31, 2021, there were 62 providers that reported they were 
engaged in the provision of prepaid card services. Of these providers, 
the Commission estimates that 61 providers have 1,500 or fewer 
employees. Consequently, using the SBA's small business size standard, 
most of these providers can be considered small entities.

Other Entities

    50. All Other Telecommunications. This industry is comprised of 
establishments primarily engaged in providing specialized 
telecommunications services, such as satellite tracking, communications 
telemetry, and radar station operation. This industry also includes 
establishments primarily engaged in providing satellite terminal 
stations and associated facilities connected with one or more 
terrestrial systems and capable of transmitting telecommunications to, 
and receiving telecommunications from, satellite systems. Providers of 
internet services (e.g., dial-up ISPs) or Voice over Internet Protocol 
(VoIP) services, via client-supplied telecommunications connections are 
also included in this industry. The SBA small business size standard 
for this industry classifies firms with annual receipts of $40 million 
or less as small. U.S. Census Bureau data for 2017 show that there

[[Page 13424]]

were 1,079 firms in this industry that operated for the entire year. Of 
those firms, 1,039 had revenue of less than $25 million. Based on this 
data, the Commission estimates that the majority of ``All Other 
Telecommunications'' firms can be considered small.

Description of Projected Reporting, Recordkeeping, and Other Compliance 
Requirements for Small Entities

    51. The Report and Order does not impose new or additional 
reporting or recordkeeping on small or other impacted entities. The 
Report and Order does require voice providers to meet certain 
obligations. These changes affect small and large companies, and apply 
to all the classes of regulated entities identified above in section D. 
The Commission allows providers 12 months after publication of the 
Report and Order in the Federal Register to comply with these 
requirements. First, all voice service providers, rather than only 
originating and gateway providers, must block calls purporting to 
originate from numbers on a reasonable DNO list. Voice service 
providers are granted flexibility to determine the appropriate list, 
based on the needs and capabilities of their networks. Additionally, 
voice service providers must use SIP code 603+ to provide immediate 
notification to callers when calls are blocked based on reasonable 
analytics.
    52. The rules adopted in the Report and Order will result in 
compliance costs for small and other entities, and may require small 
entities to hire professionals to comply. While the record does not 
contain specific cost data estimates or analysis, the Commission 
believes that the burdens associated with the rules it adopts today 
will be modest. The requirement to block based on a reasonable DNO list 
is a modest extension of an existing rule. Similarly, implementation of 
SIP code 603+ is unlikely to impose significant new costs as it can be 
implemented as part of routine maintenance.
    53. Although small and other entities will incur costs to implement 
the requirements of the Report and Order, based on the record the 
benefit of these requirements will exceed their costs. The Commission 
notes in the Report and Order that the industry estimates that 
consumers receive 13 spam or fraud calls a month, and on average those 
scammed by phone lose $865. Moreover, based on complaint data from the 
Federal Trade Commission (FTC) the median loss for fraud by phone was 
$1480. Further, the FTC reports a total of $850 million lost to fraud 
by phone call.

Steps Taken To Minimize the Significant Economic Impact on Small 
Entities, and Significant Alternatives Considered

    54. The RFA requires an agency to provide, ``a description of the 
steps the agency has taken to minimize the significant economic impact 
on small entities . . . including a statement of the factual, policy, 
and legal reasons for selecting the alternative adopted in the final 
rule and why each one of the other significant alternatives to the rule 
considered by the agency which affect the impact on small entities was 
rejected.''
    55. In the Report and Order, the Commission considered various 
alternatives and took the steps discussed below to minimize the 
economic impact for small entities, and address concerns small entities 
raised in comments. The Commission declined to adopt additional 
protections for lawful callers. The Commission extended the existing 
rule requiring blocking of calls based on a reasonable DNO list to all 
voice providers, rather than only originating and gateway providers, 
consistent with small and other providers that broadly support this 
proposed extension. The Commission declined to expand the scope of the 
list, or to mandate the use of a single uniform list, in part to ensure 
that providers with more limited resources and older equipment, which 
would include many smaller providers, are able to adopt lists that are 
appropriate for their networks and should address the concerns raised 
by some small entity commenters. The Commission also considered but 
declined to adopted a safe harbor from liability for providers based on 
use of a reasonable DNO list requested by small entity advocates since 
the Commission is not aware of what liability a provider would face for 
blocking based on a such a list, or of any provider encountering any 
such liability since the Commission authorized this type of blocking in 
2017. The Commission likewise declined to adopt a reasonable analytics-
based blocking mandate, reducing the burden on smaller providers which 
was a concern raised in comments.
    56. In addition to the blocking requirements, the Report and Order 
adopted a single SIP code for notification to callers when calls are 
blocked based on reasonable analytics, SIP code 603+. This modifies the 
Commission's existing rule allowing for use of one of a list of several 
codes, which has always been intended as a temporary measure. Support 
both for, and against the use of SIP code 603+ were in comments filed 
by small entities. Based on the record, SIP code 603+ which builds on 
the existing SIP code 603 will provide more information to providers 
more quickly than SIP code 608, builds on the existing SIP code 603, 
and appears to be substantially less technically complex to implement 
making it the more appropriate choice for the Commission. As the 
Commission discusses in the Report and Order, whether the Commission 
chose SIP code 603+ or 608, small and other callers would be required 
to make modifications to comply. To ensure that small and other 
providers have adequate time to implement the Report and Order 
requirements, the Commission modified and expanded the implementation 
deadline it proposed in the Call Blocking NPRM. All providers have 12 
months from publication of the Report and Order in the Federal Register 
to make the transition, which addresses small provider concerns about 
the implementation timeframe and requests for additional time. The 
Report and Order also allows for use of an ISDN User Part (ISUP) code 
where the network is non-IP.

Report to Congress

    57. The Commission will send a copy of the Report and Order, 
including this FRFA, in a report to be sent to Congress pursuant to the 
Congressional Review Act. In addition, the Commission will send a copy 
of the Report and Order, including this FRFA, to the Chief Counsel for 
Advocacy of the SBA. The Report and Order and FRFA (or summaries 
thereof) will also be published in the Federal Register.

Ordering Clauses

    58. It is ordered that, pursuant to sections 4(i), 4(j), 201, 202, 
217, 227, 251(e), 301, 303, 307, 316, and 403 of the Communications Act 
of 1934, as amended, 47 U.S.C. 154(i), 154(j), 201, 202, 217, 227, 
251(e), 301, 303, 307, 316, and 403, this Report and Order is adopted.
    59. It is further ordered that the revisions to Sec.  64.1200(o) 
shall be effective 90 days after publication of a notice of Office of 
Management and Budget approval in the Federal Register of information 
collection requirements under the Paperwork Reduction Act, and the 
revisions to Sec.  64.1200(k)(9) shall be effective 12 months after 
publication in the Federal Register.

List of Subjects in 47 CFR Part 64

    Communications common carriers, Reporting and recordkeeping 
requirements, Telecommunications, Telephone.


[[Page 13425]]


Federal Communications Commission.
Marlene Dortch,
Secretary, Office of the Secretary.

Final Rules

    For the reasons discussed in the preamble, the Federal 
Communications Commission amends 47 CFR part 64 as follows:

PART 64--MISCELLANEOUS RULES RELATING TO COMMON CARRIERS

0
1. The authority citation for part 64 continues to read as follows:

    Authority:  47 U.S.C. 151, 152, 154, 201, 202, 217, 218, 220, 
222, 225, 226, 227, 227b, 228, 251(a), 251(e), 254(k), 255, 262, 
276, 403(b)(2)(B), (c), 616, 620, 716, 1401-1473, unless otherwise 
noted; Pub. L. 115-141, Div. P, sec. 503, 132 Stat. 348, 1091; Pub. 
L. 117-338, 136 Stat. 6156.

Subpart L--Restrictions on Telemarketing, Telephone Solicitation, 
and Facsimile Advertising

0
2. Sec.  64.1200 is amended by revising paragraphs (k)(9) and (o) to 
read as follows:


Sec.  64.1200  Delivery restrictions.

* * * * *
    (k)(9) Any terminating provider that blocks calls based on any 
analytics program, either itself or through a third-party blocking 
service, must immediately return, and all voice service providers in 
the call path must transmit, an appropriate response code to the 
origination point of the call. For purposes of this rule, an 
appropriate response code is:
    (i) In the case of a call terminating on an IP network, the use of 
Session Initiation Protocol (SIP) code 603+, as defined in ATIS-
1000099, adopted August 16, 2022;
    (ii) In the case of a call terminating on a non-IP network, the use 
of ISDN User Part (ISUP) code 21 with the cause location ``user'';
    (iii) In the case of a code transmitting from an IP network to a 
non-IP network, SIP code 603+ must map to ISUP code 21; and
    (iv) In the case of a code transmitting from a non-IP network to an 
IP network, ISUP code 21 must map to SIP code 603 or 603+ where the 
cause location is ``user.''
* * * * *
    (o) A voice service provider must block any calls purporting to 
originate from a number on a reasonable do-not-originate list. A list 
so limited in scope that it leaves out obvious numbers that could be 
included with little effort may be deemed unreasonable. The do-not-
originate list may include only:
    (1) Numbers for which the subscriber to the number has requested 
that calls purporting to originate from that number be blocked because 
the number is used for inbound calls only;
    (2) North American Numbering Plan numbers that are not valid;
    (3) Valid North American Numbering Plan Numbers that are not 
allocated to a provider by the North American Numbering Plan 
Administrator; and
    (4) Valid North American Numbering Plan numbers that are allocated 
to a provider by the North American Numbering Plan Administrator, but 
are unused, so long as the provider blocking the calls is the allocatee 
of the number and confirms that the number is unused or has obtained 
verification from the allocatee that the number is unused at the time 
of blocking.
* * * * *
[FR Doc. 2025-04811 Filed 3-21-25; 8:45 am]
BILLING CODE 6712-01-P