Foreign Property Gain - Reporting Year Allocation

Dear Team at HMRC, I am a UK resident since 1991 and pay UK tax on the arising basis. From HMRC's reply to a post I can see that the determining factor for the tax year in which a property gain has to be reported is the tax year into which the date of exchange of contracts falls (UK property). There is no exchange of contracts in Germany. Instead vendor and buyer both sign the contract at an appointment with a notary public. I assume into whichever tax year the day of the appointment with the notary public falls will be the reporting tax year for the gain. I have sold a buy-to-let property in Germany with a notary appointment (contract signing) on 2 March 2023 (in UK tax year 2022/23). The sale proceeds were received on 27 April 2023, keys handed over on 2 May 2023 (in tax year 2023/24). According to my research I will need to report the property gain in my self assessment for tax year 2022/23. Any help regarding the tax year when this foreign property gain needs to be reported gratefully received. Thank you in advance.

Hi,
The UK uses the completion date of the transaction, to determine the tax year into which a capital gain arises.  
In the absence of a completion date, you would have to use an alternative, such as the date the legal transfer of the asset takes place, using the laws of that particular country.  
It is not likely to be the date that money changes hands.
Thank you.