CGT trigger on sales process of French holiday home disposal. Exhange & completion equivalents

In the UK my understanding is that CGT becomes liable on 'exchange' rather than 'completion' when selling a second home. I have a holiday home in France which I've owned for almost 20 years and therefore CGT may be due in the UK if I decide to sell (unless the French authorities who have first dibs on CGT claim more than the UK). My question is does HMRC follow the same rules re the point at which CGT liability is triggered? By this I mean does HMRC equate the 'compromis de vente' which in France is the first legal stage of the sales process when parties agree to the terms of the sale in a binding agreement as the equivalent of the UK'exchange' and which is then followed, typically two months later by what the French term 'l'acte de vente' or 'completion 'in UK parlance? In a nutshell does the 'compromis de vente' = 'exchange and 'l'acte de vente' ='completion'.

Hi,
You declare at the date of exchange/completion in the UK.
Thank you.