How to Document a Used Car Purchase Issue or Dispute

Used car disputes typically involve one of three problems: the car was misdescribed in the advertisement, a fault was present at the time of sale and not disclosed, or a warranty or guarantee is being denied. Proving any of these requires specific documentation collected at specific times. This guide covers what to gather and when.

The advertisement: screenshot it immediately

The listing as it appeared when you bought is the baseline for any "not as described" claim. Sellers frequently take down or edit listings after a complaint is raised.

• Screenshot the full listing — the title, all photos, the mileage, the vehicle history claims ("one owner," "no accidents," "full service history"), and any warranty offered.
• Archive the URL using a web archiving service if the listing is still live.
• If you bought through a dealer, keep any printed brochure, email, or written quote they provided before purchase.
• Save any specific written representations the seller made about the vehicle's condition — "new clutch," "recent timing belt," "engine just serviced."

Purchase contract and payment records

• Signed purchase contract or receipt showing the agreed price, vehicle details (registration, VIN/chassis number, mileage at point of sale), and any warranty or guarantee terms.
• Any "sold as seen" or exclusion clauses in the contract — these are legally relevant and you need the exact wording.
• Payment records — bank transfer confirmation, card statement, or receipt for cash. Match these to the contract amount.
• Any part-exchange agreement if you traded in a vehicle as part of the deal.

Pre-purchase inspection records

If you had the vehicle independently inspected before purchase, those records are valuable evidence of what the car's condition was at the point of sale.

• The written inspection report from the independent inspector, with any faults or advisories noted.
• Any MOT, roadworthy certificate, or vehicle history check you obtained before buying.
• If the seller refused to allow an inspection, note this in writing (email the seller: "Just confirming our call — you advised that an independent inspection would not be possible before collection.").

Documenting faults discovered after purchase

A key issue in used car disputes is whether a fault was present at the time of sale or developed afterward. The sooner you document it after purchase, the stronger the evidence.

• Photograph or video the fault clearly as soon as it is discovered — dashboard warning lights, fluid leaks, bodywork defects, or mechanical failures.
• Get a written diagnostic report from a mechanic as early as possible. The report should state what the fault is and, ideally, an opinion on whether it was likely pre-existing at the time of sale.
• Keep all repair invoices and estimates for the fault, with the mechanic's name and contact details.
• Record the odometer reading at the time you discovered the fault and at every subsequent repair visit.

Vehicle history documents

• Vehicle history report obtained at purchase (showing accident history, mileage anomalies, finance outstanding).
• Service history booklet or records provided by the seller — if you were told the car had a full service history and it was not in the vehicle when you collected it, note this.
• Registration document confirming ownership transfer.

Seller communication after the sale

• Save every message or email to and from the seller after the fault was discovered.
• Log any phone calls: date, time, what was said and what was offered or refused.
• If the seller agreed to contribute to a repair cost or offered a refund in writing, keep that message separately — it may constitute a relevant admission.
• If you formally rejected the vehicle and requested a refund, send this in writing and keep proof of delivery.