Code of Massachusetts Regulations
220 CMR - DEPARTMENT OF PUBLIC UTILITIES
Title 220 CMR 26.00 - Security Deposits and Late Payment Charges Applicable to Non-residential Customers
Section 26.09 - Interest Rate Paid on Deposits

(1) All cash or cash-equivalent security deposits held for more than six months from the date of deposit shall be paid interest thereon, commencing from the date of payment to the date of refund. The rate of interest shall be the equivalent of the rate paid on two-year, United States Treasury notes for the preceding 12 months ending December 31st of any year.

(2) Such rate shall be the rate published during the first week of January in the Federal Reserve Statistical Release, H.15 Selected Interest Rates. The company shall determine said rate and file with the Department the rate to be paid on all security deposits within 15 days after such rate is reported in the Federal Reserve Statistical Release. This rate shall be the rate paid on all deposits held during the remaining calendar year or other applicable time period regardless of when such security deposit was paid during that period.

(3) Said interest shall be compounded annually on December 31st and the accrued interest shall be applied toward a customer's bill during the next billing cycle, provided, however, that only deposits made by cash or cash equivalent shall be paid interest thereon. Deposits made by other acceptable means shall not be paid interest.