N.H. Rev. Stat. Ann. § 90:5

In any case where it is determined by the board of arbitration referred to in RSA 90:4 that the decedent died domiciled in this state, 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, 4 percent of the amount of the taxes per annum.