UK residents with foreign income or gains: double taxation relief: Withdrawal of credit claims
A claim to credit relief, once made, may be withdrawn at any time before the assessment giving effect to the claim becomes final and conclusive. Under self assessment, a claimant may amend the claim at any time during the 12 month period following the date on which it was made, unless the claim is under enquiry.
If it is under enquiry, the claimant will be able to amend the claim when the enquiry is complete. If the claim to credit relief is withdrawn, the foreign tax is deductible under TIOPA10/S112-S113. See INTM162580 where there has been an adjustment to the amount of foreign tax paid.