ANnEU directive is in force which does allow for such information-sharing between EU states.
French and EU sources say the UK is integrated into an electronic information sharing system.
It means France can obtain the UK address of registered owners of British cars to send fines in the post.
Whether this continues after a Brexit depends on future negotiations.
A spokesman for the French Interior Ministry’s road safety section said people who receive fines must pay them or risk having to pay later at an increased rate, which would apply if they are ever stopped again by police in France and checks are made.
Increasingly sophisticated methods are also in place to chase people up for fines in their home country. This includes the possibility of home country officials collecting fine money.
This edited Q&A is taken from our Owing a Secon Home in France helpguide. Order at the helpguide section of connexionfrance.com