The prefecture in Nantes previously assured us that it is speeding up processes for this after teething problems with new computer systems.
However, it advises not to wait until your old licence is about to expire before applying to swap it and also not to send your British (or other EU country) licence until you have received the attestation de dépôt letter that you can show to police in case of being stopped.
Once received, this attestation lasts up to 12 months, the prefecture said.
The prefecture told us that gendarmes are aware of the problems and will usually not be strict about an EU citizen driving on a recently-expired licence because they are waiting for the attestation to come.
As for your car insurance, an adviser from AXA Agence International, which provides an English-speaking insurance service in France, said it is not a problem if your photocard licence has expired as long as your right to drive is still valid (if your right to drive is subject to a limit, this is shown with a different date on the back of the card).
In the case of British licences, the photocard expires after 10 years but the validity date of your right to drive is shown on the back (usually at age 70, after which the card needs to be renewed if you live in the UK. It is not possible to renew it without a UK address and you must swap to a French licence).
The AXA adviser said: “In the case of a UK licence, if it’s only the photocard that’s expired, you’re still legally allowed to drive.”
She said the same would apply on a trip back to the UK (although there could be issues with police or car hire firms if you cannot show a current licence).