Vt. Stat. Ann. tit. 32, § 5873

For good cause shown, the Commissioner may extend the time for the payment of any tax liability, but the taxpayer shall pay, at the time the 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 liability was originally due to the time of payment.