Taxation on Foreign Income

Taxation in UK is applicable on your global income and this makes it quite complicated as tax is applicable on the income in the country where it is originated as well.

Till end of year 2024-25, foreign income taxation could be opted as remittance basis or arising basis for non-domiciled residents (known as non-dom. regime). Now, this is abolished and starting financial year 2024-25 all residents in the UK would be taxed for their global income on arising basis.

New residents would still get waiver on all foreign income for first 4 years with certain conditions. If you have been in the UK for 4 years on 5th April 2025, you would have exhausted this waiver already (whether you claimed it or not)

What next - you need to include all income in foreign territories on UK self-assessment tax return and calculate tax on the same after considering DTAA (Double Taxation Avoidance Agreement) provisions with the country where the income has originated. This is irrespective of the fact whether that income is taxable or tax free in that foreign country and whether or not you have filed tax returns in the foreign country
Eg. Interest on NRE deposits is tax-exempt in India but taxable in the UK as foreign income

Lastly, minimal foreign income was considered as deemed remittance basis till FY 2024-25 but not any more and hence do not forget to include all of this on your self assessment tax returns.