793Reduction of United Kingdom taxes by amount of credit due
(1)Subject to the provisions of this Chapter, where under any arrangements credit is to be allowed against any of the United Kingdom taxes chargeable in respect of any income or chargeable gain, the amount of the United Kingdom taxes so chargeable shall be reduced by the amount of the credit.
(2)Nothing in subsection (1) above authorises the allowance of credit against any United Kingdom tax against which credit is not allowable under the arrangements.