Declaring Foreign Bank Interest

Dear HMRC, Can you please help advise on how I declare foreign bank interest on my U.K. tax return (arising basis, UK resident/ordinary resident/domicile) in the following two scenarios: 1. I receive $1000 of bank interest but the foreign country did NOT withhold any tax on it as they were not aware that I became a non-resident of that country? If I told them I was non-resident, they would withhold 25% tax on the interest. Because no tax was withheld, do I declare $1000 on my U.K. tax return? Where do I fill this in on the self-assessment return form? 2. I receive $1000 of bank interest and the foreign country DID withhold 25% tax on it? Do I have to declare this on my U.K. tax return? If so, do I declare $1000 or $750 (net of tax I already paid)? Am I taxed again on the $750 in the U.K? If I can claim a foreign credit, how do I do that when filling in the self-assessment form? One separate question as well if you don't mind: 3. Separately, if I have unrealized gains in my tax-free investment account overseas (which is not tax exempt in the DTA), I don’t have to declare anything for in the U.K. tax return as it is unrealized gain/loss? If I did sell and realize a gain, how do I declare this on my U.K. self-assessment return? Thank you!

Hi Yoga1,
We cannot advise on scenarios.  Overseas interest and tax deducted is declared on SA106 (foreign).  Overseas capital gains are declared on SA108 (capital gains) and SA106 (foreign) in the tax year that they arise.
Thank you.