Adjustments where suppositions cease to be reasonable
259L
(1) Where— (a) a reasonable supposition is made for the purposes of any provision of this Part, and (b) the supposition turns out to be mistaken or otherwise ceases to be reasonable, such consequential adjustments as are just and reasonable may be made. (2) The adjustments may be made (whether or not by an officer of Revenue and Customs) by way of an assessment, the modification of an assessment, amendment or disallowance of a claim, or otherwise. (3) But the power to make adjustments by virtue of this section is subject to any time limit imposed by or under any enactment other than this Part. (4) No adjustment is to be made under this section on the basis that an amount of ordinary income arises, as a result of a payment or quasi-payment, to a payee after that payee's last permitted taxable period in relation to the payment or quasi-payment (see section 259LA, which makes provision about certain such cases).