Late payment surcharge for gift tax: monthly surcharge accrues on assessed tax during default, capped by an aggregate limit. The amendment substitutes clause (i) of section 17 to levy a monthly surcharge equal to two per cent of the assessed tax for every month of default, not exceeding in the aggregate fifty per cent of the assessed tax, in addition to the gift-tax payable. It defines assessed tax as the gift-tax chargeable under the Act reduced by the amount for which credit is allowed under section 18, and deems the substitution effective from 1 April 1963.