Jane is right, Charles.
The point is that if you are a visitor with your main residence in another EU country, you may use your car here for six months out of a year. It must meet the legal requirements of that country, though, so for a UK car to be legally on the road ANYWHERE, it must be taxed in the UK, insured by a member of the British Motor Insurers Bureau & have a current UK MOT. The only exception is if a vehicle is going through the import process (EEC Directive 2009/103/EC para 27). If you do not notify your insurance company of your longer term stay abroard (beyond their usual 30 day cover, for example) YOU DO NOT BECOME UNINSURED! All that happens is that your cover drops to the minimum legal requirement.
Basically the rules are very simple & are similar in all countries in the world.
If you are a resident of a country, ie the country you actually live in rather than have a holiday home in, you can only drive a car registered in that country. So if you live here in France your car must be registered here, be insured by a French company (not its UK branch) & have a French controle technique. If you already live here but buy a UK car to import you must do this within ONE month of it arriving on these shores. During this time your (honest) French agent can provide you with insurance cover on your UK number on a month by month basis, with a limit of 6 months, to enable the importer to deal with all the paperwork.
Likewise for a UK car to be legally used abroad it must be owned by a UK resident, be insured by an insurance company who is a member of the British Motor Insurers Bureau, be taxed & have a current MOT. Cars on SORN are exactly that - off road, ALL roads. The reason that it is illegal to drive a foreign vehicle here is obvious.
No country is going to allow its citizens to race around in a car that cannot be easily traced. This would in effect give anyone carte blanche to disregard the rules of the road & drive like a complete idiot, knowing that they are untraceable as at the moment the gendarmes cannot access the DVLA computer, which, even when this is possible would effectively have a false address - the bit about UK residency applies.
This also means that should a member of your family visit you here from the UK, you can only drive their car if they are in it with you. You cannot borrow the car to nip to the shops.
Driving with a foreign registration number
UK residents aren’t allowed to use non-UK registered vehicles on UK roads. The only exceptions are if you:
- work in another European Union (EU) member state and use an EU-registered company car temporarily in the UK
- lease an EU-registered car and use this temporarily in the UK
The French law is similar, just substitute "UK" for "French".
Si vous venez d'acquérir un véhicule d'occasion provenant de l'étranger, vous devez faire établir le certificat d'immatriculation (ex-carte grise) dans le mois suivant la date d'achat du véhicule.
http://vosdroits.service-public.fr/particuliers/F19222.xhtml
Ireland also has a 30 day rule
"If you bring a vehicle into Ireland from abroad, you must have proof of identity and other specified documents in order to register and pay the VRT. There is a list of the required documentation on the Revenue website.
Within 7 days of your vehicle arriving in Ireland, you must book an appointment with the NCTS for it to be inspected - see 'How to apply' below. At the inspection the vehicle will be examined to ensure its characteristics match those recorded in the registration documentation. You pay the VRT charged after your vehicle has been inspected at the NCTS centre. The registration process must be completed within 30 days of the vehicle's arrival in Ireland."
If you spend more than 183 days a year in France you are a French resident - that is 183 in 365 days, not, as some think, 6 months consecutively. This makes sense otherwise you would have foreign registered cars committing all kinds of traffic offences in another country with no fear of getting a knock on the door or at least a ticket dropping on to the door mat! The big problem we have here is that for a UK car to be legally driven abroad (by a visitor) it must still conform to all UK rules, ie be taxed, have a UK MOT & UK insurance. Not on a SORN, or with a French CT (although with a CT & french insurance at least SOME attempt has been made to make the car comply a bit). Many UK cars I have seen have nothing. In the event of a serious accident an innocent party can have his life ruined with absolutely no recompense at all. In the UK such cars are impounded. Many are then crushed. The French do the same. They do not generally target UK registered cars with an up to date tax disc & in fact the confiscation of cars is not limited to foreign cars. If you exceed the speed limit by more than 50 kph three times your car will be confiscated & sold.
All this information is available on Government websites, both English & French, just google your specific question.
Many UK insurance companies make it a term of their cover that the insured is a UK resident, which if you live in France you are not.
I. - Le fait de faire circuler, sur les voies ouvertes à la circulation publique un véhicule à moteur ou une remorque sans que ce véhicule soit muni des plaques ou inscriptions exigées par les règlements et, en outre, de déclarer un numéro, un nom ou un domicile autre que le sien ou que celui du propriétaire est puni de cinq ans d'emprisonnement et de 3 750 euros d'amende.
II. - Toute personne coupable de cette infraction encourt également les peines complémentaires suivantes :
1° La suspension, pour une durée de trois ans au plus, du permis de conduire, cette suspension pouvant être limitée à la conduite en dehors de l'activité professionnelle ;
2° La confiscation du véhicule.
III. - Ce délit donne lieu de plein droit à la réduction de la moitié du nombre maximal de points du permis de conduire.
I think you will find this law to be fairly international.
https://www.gov.uk/government/news/government-crackdown-on-illegal-foreign-registered-vehicles