Tax on dividend (Poland) double taxation treaty with UK

Hi, I have a question regarding tax due on foreign dividend payment. To provide some context - I've inherited a stake in a Polish company and now I own ~10% shares (the company is not stock listed). The company will be soon paying out a cash dividend for 2023 and according to Polish law 19% tax is withheld at source. I live, work (full-time employment) and pay taxes in the UK. I would like to understand how to appropriately report this income in the UK and tax implications. Is my understanding correct that: 1) I would disclose this dividend as part of my self-assessment for year 2024/2025 (for other reasons I complete a self-assessment every year)? 2) Since tax was already paid in Poland on the dividend, no additional tax will be due on that in the UK? If yes, should I attach proof that tax was paid alongside my self assessment? In addition, the company's accountant advised that there is a possibility to withhold only 10% tax in Poland provided I submit a certificate of residence demonstrating that I live and pay taxes in the UK. Given this I would like to understand - Is that a possibility and, if yes, would the additional tax due be then charged by HMRC following filing of the self-assessment (I am a higher rate tax payer so then would expect to pay 20% CGT in the UK whereas I would have paid only 10% in Poland)? Many thanks!

Hi,

Please refer to:

Tax on foreign income

Thank you.