Frédéric ******************
@Dave ********
It's not a matter of citizenship but residency. If you're resident in the UK (whatever your citizenship is) you can use your driving license abroad during holidays (international standard is 90 days). If you become resident of another country, you're supposed to exchange your British licence with a local one and you can use it in the UK if you come for vacations. The good thing with Thailand is that they don't keep your British licence like they do in many county (ie Canada, Australia, USA, all Europe) when they give you the Thai one.