QWithholding tax (paid in Poland) and UK CT - Can I deduct the Withholding tax (paid in Poland)

Can I deduct the Withholding tax (paid in Poland for example, but it might be any other country) while charging UK Corporation Tax to lower profit? You said in another thread ,,You can claim double taxation relief in the company tax return for the relevant accounting period. If you have already filed a tax return, you may be able to amend it to include the relief" here: https://community.hmrc.gov.uk/customerforums/bt/1196bbff-449e-ee11-a81c-002248c69e85 Do you mean: 1) We can claim it always when the withholding tax was paid in another country 2) We can claim it always when the withholding tax was paid in another country but only if some extra conditions were met 3) We can claim it only after contacting HMRC with a particular case, and receiving HMRC's permission? Please, I need more info :)

Hi

Guidance in relation to this subject can with found within the 'International Manual', reference INTM167000, which is available via GOV.UK.
A claim is normally made at the time of filing the Company Tax Return, no prior permission is required.
The amount of foreign tax allowed against Corporation Tax on any income, cannot exceed the Corporation Tax attributable to that income.
For example if withholding tax had been suffered at 30% and the income in the UK was chargeable at 19%, relief could only be allowed at 19%.
A claim must be made within 4 years from the end of the accounting period in which the tax was paid.
If you failed to make a claim when you submitted your initial Company Tax Return, then you may file an amendment, within the specified time limit.
Where there is a Double Taxation Agreement with the other country, relief  from double taxation is usually achieved by the credit method.
Where relief is not given under an agreement, the UK gives credit unilaterally to UK residents.  

Thank you