Does a V5C prove the seller owns the car?

No. A V5C identifies the registered keeper and vehicle record; it is not proof of legal ownership by itself.

In relation to “Does a V5C prove the seller owns the car?”, treat the advert as a set of claims to verify. The registration, VIN, mileage, history and condition should tell the same story.

For “Does a V5C prove the seller owns the car?”, treat the V5C as one identity check, not the whole purchase check. Match the registration, VIN and vehicle details to the physical car and the latest official record.

For “Does a V5C prove the seller owns the car?”, keep a dated receipt and evidence of the keeper change. The exact transfer time can be useful if parking, toll, tax or enforcement correspondence appears later.

For “Does a V5C prove the seller owns the car?”, this answer is written for a Northern Ireland user, but some vehicle-registration, consumer-credit and insurance functions operate on a UK-wide basis. The attached sources — GOV.UK - Buy a vehicle: step by step, GOV.UK - Vehicle registration: new and used vehicles, and nidirect - Contact Consumerline — are therefore deliberately mixed where the responsible authority is UK-wide. That is more accurate than forcing every point into an NI-only source.

Practical next step for “Does a V5C prove the seller owns the car?”: do not pay until this point has been independently checked. Save the advert, seller messages and any official or commercial check so you can show exactly what information you relied on.