For good cause shown, the Commissioner may extend the time within which a taxpayer is required to file a return. An extension of the time in which to file a return will result in a corresponding extension of the time for the payment of the tax liability with respect to which the return is filed, provided that the taxpayer shall pay, at the date that tax liability is paid, without assessment or demand, interest computed at the rate per annum established from time to time by the Commissioner pursuant to section 3108 of this title on the unpaid amount of that tax liability from the time when the tax liability was originally required to be paid to the time of payment.
32 V.S.A. § 7481