(1)As soon as practicable after a claim is made, amended or corrected—
(a)WRA must issue notice of its decision to the claimant, and
(b)where WRA decides to give effect to the claim or amendment (whether in part or in full), it must do so by discharge or repayment of devolved tax.
(2)Where WRA enquires into a claim or amendment—
(a)subsection (1) does not apply until a closure notice is issued under section 75, and then it applies subject to section 77, but
(b)WRA may at any time before then give effect to the claim or amendment, on a provisional basis, to such extent as it thinks fit.