Hi,
The German state pension is now only taxable in Germany from 1 August 2017. Article 17 of the UK / German double taxation agreement, advises German Government bases pensions are normally taxable only in Germany, except where you are a national and resident of the UK, in receipt of a government pension, then in those cases, the pension is taxable in the UK. If article 17 does not cover your pension, you may consider article 21 other income.
Article 18 of the UK / France double taxation agreement, advises that French government pensions are normally only taxable in France. For a French government pension to be taxable in the UK, you will need to be a national and resident of the uk, but also, not a national of France. If article 18 does not apply to your pension, then you man consider article 23 other income article
If you need to amend your tax returns to remove foreign pensions not taxable in the UK, you can amend your 2021 to 2022 tax return up to 31 January 2024, 2022 to 2023 (31 January 2025). For 2019 to 2020 & 2020 to 2021, you will need to submit an overpayment relief claims following the instructions at:
SACM12150 - Overpayment relief: Form of claims
Thank you.