(1) Section 57 of the Principal Act is amended -

(a) in subsection (1) by substituting the following for the definition of "tax":

"'tax' includes probate tax, payment on account of tax, interest charged, a surcharge imposed or a penalty incurred under any provision of this Act.",

and

(b) by substituting the following for subsection (3):

"(3) Notwithstanding subsection (2), no tax shall be repaid to an accountable person in respect of a valid claim unless that valid claim is made within the period of 4 years commencing on -

(a) 31 October in the year in which that tax was due to be paid in accordance with section 46(2A), or

(b) the valuation date or the date of the payment of the tax concerned (where the tax has been paid within 4 months of the valuation date) in respect of inheritances to which sections 15(1) and 20(1) apply.".

(2) This section shall apply as respects any claim for repayment (within the meaning of the Principal Act) made on or after the passing of this Act.