220 CMR, 52.551
This account shall include the amount of taxes applicable to the water operations of the accounting company during the period for which the income account is stated, including the tax levied upon the gross operating revenue to cover the yearly expenses of this Department.
The tax accounts shall be charged at regular accounting intervals and the "Tax Liability Account" concurrently credited with the period's proportion of taxes applicable to the operations covered by each amount. If the exact amounts of the annual taxes are not known, they shall be estimated and a due share of the estimated amounts shall be charged for each accounting period. From time to time during the year as the actual tax levies become known the periodic charges shall be adjusted so as to include as nearly as possible the total amount of the taxes in the period to which they apply.
220 CMR, 52.551