Mass. Gen. Laws ch. 40, § 21E: Municipal charges and bills; due dates; interest

Section 21E. Any city or town may, by ordinance or by-law, and any district by vote of the district meeting, establish due dates for the payment of municipal charges and bills, and may fix a rate at which interest shall accrue if such charges remain unpaid after such due dates; provided, however, that the rate of interest shall not exceed the rate at which interest may be charged on tax bills under the provisions of section fifty-seven of chapter fifty-nine.