A valid driving licence covering you for the vehicle you are driving/riding. Old style UK paper driving licences are still OK until you reach age 70. You do not need an International Driving Permit (IDP) for driving in France, but you do for some EU countries.
An up-to-date passport for each occupant of the vehicle
(Passport must be less than 10 years old & have at least 3 months before it expires on the day you return)
Vehicle insurance documents, proving at least third-party cover
A valid MOT certificate if your vehicle is over 3 years old
V5 log book or a VE103 document for rented/hired vehicles
A UK Sticker (replaced the GB sticker from September 2021)
A warning triangle (Not for motorbikes)
Reflective helmet stickers for motorcycle riders²
It is illegal to drive with an important bulb gone. Having a spare bulb kit will help to avoid this
A High Visibility Vest for each occupant of the vehicle
Your vehicle (and any trailer/caravan/boat you are towing) should be displaying a UK sticker
An Animal Health Certificate from your Vet for any pets you have with you
A valid visa if your stay will take you over 90 days in any 180-day period
² There is some suggestion that this only applies to helmets made or sold in France. So for more information read our Motorcycling in France
Here is a comprehensive French driving kit, that has all the legal items you need and a couple of great optional extras thrown in. You will save money with the kit over the cost of buying the items individually.