Section 25 | Credit not allowed if relief allowed against overseas tax
From legislation.gov.uk
(1)Subsection (2) applies if relief may be allowed—
(a)under the arrangements, or
(b)under the law of the non-UK territory in consequence of the arrangements,
in respect of an amount of tax that would, but for the relief, be payable under the law of that territory.
(2)Credit under section 18(2) is not allowed in respect of that tax, whether or not the relief has been used.