Mass. Gen. Laws ch. 65B, § 5: Penalties and interest for non-payment of tax

Section 5. In any case where it is determined by the board of arbitration referred to in section four that the decedent died domiciled in this commonwealth, penalties and interest for nonpayment of the tax, between the date of the election and the final determination of the board, shall not exceed, in the aggregate, four per centum of the amount of the taxes per annum.