hi, can I register myself in France and still live and pay my taxes in the U.K.
Not sure what you mean by "can I register myself in France". Register yourself for what?
As far as tax goes, there is a UK_France tax treaty that sets out in great detail where a person pays their taxes if they have connections to both countries. You don't get any choice in the matter, you follow the rules in the treaty.
But it is not obvious what your connection to France would be, if you are a UK citizen and you live in the UK.
hi thanks for the reply, I mean can I register as a French resident, but I think I have answered my own question
LOL, well yes, if you live in the UK not in France then you can't register as a French resident ;-)
Post Brexit you can't in any case simply decide to live in France. You have to apply for a visa and go through the immigration process.
One way and the other I guess the answer is No, whichever way you look at it.