W8BEN double taxation

I filled out earlier in the year a W8BEN tax form to recieve royalties, these were subject to 15% witholding tax, I was told by someone at HMRC I have to further declear the income but can do so in 2025, my question is since the IRS has taken 15% of the total amount so far, will the income in the UK be charged at a 100% rate in everysingle income bracket? so for example if the overall payment was over the 45% threshold will there be tax relief since 15% has already been taken by the IRS or will it be taxed as any normal income in the UK?

Hi ENThomas,
The UK will tax the income at your highest rate based on your overalll income. you can then claim foreign tax credit relief for the US tax paid -
Tax on foreign income Skip to contents of guide Contents
Thank you.