If you've ever trusted a log file a bit too much, you already know the trap with buying a used car in the UK. The V5C (the "log book") looks official, it's printed on watermarked paper, and it has the seller's name on it. So it must prove they own the car, right?

It doesn't. And knowing exactly what it does and doesn't tell you saves a lot of grief.

Quick disclosure: I'm part of the small team behind CarCheckHQ, a UK car history check site. This post isn't a pitch though. Most of what follows is free to do yourself.

The one-line version

A V5C names the registered keeper, not the owner. GOV.UK says it plainly: the V5C is not proof of ownership.

The keeper is the person who gets the letters, the parking tickets and the speeding notices. The owner is whoever actually paid for it. Often that's the same person. Plenty of times it isn't:

  • Company cars, where the business owns it but the driver is on the log book.
  • Lease cars, where the leasing company usually sits on the V5C and a finance company owns it.
  • Hire purchase, where you don't own the car until the last payment clears.
  • Couples, where one name is on the paper and the car is shared.

So when a seller waves the log book at you, read it like a log entry. It tells you something real happened. It doesn't tell you the whole story.

What the V5C is genuinely good for

Think of it as a checksum. It's brilliant for spotting things that don't match:

  1. VIN and engine number. Find the VIN on the car (usually the base of the windscreen and a plate in the door frame) and check it against the log book. If they differ, walk away. No exceptions.
  2. Registration, colour and make. Put the reg into GOV.UK's free vehicle enquiry and compare. A blue car that the record says is silver is worth a question.
  3. The paper itself. Hold it up to the light and look for the "DVL" watermark. GOV.UK also publishes the serial number ranges of blank V5Cs that were stolen, so it's worth a look.
  4. Is it the latest one? The free GOV.UK service shows the date the last V5C was issued. If the seller's copy is older than that, someone has a newer log book, and you want to know who.
  5. Keeper's address. Ideally you're viewing the car at the address printed on it.

What it can't tell you

This is where people get caught out. The log book says nothing about:

  • Outstanding finance. A car with an HP agreement still running can have a perfectly normal V5C.
  • Whether the seller has the right to sell it.
  • Most write-off history. A Cat S car's log book should show the category, but a Cat N one won't.

We wrote up the keeper versus owner question in more detail in our guide on whether a V5C proves ownership, with the GOV.UK and Citizens Advice sources linked.

So how do you actually check ownership?

Ask for proof beyond the log book. Things a genuine private seller can usually show:

  • The original purchase invoice or receipt with their name on it.
  • A finance settlement letter if they had a loan or HP on it.
  • Service history with matching names and addresses.

If the seller isn't the registered keeper, ask why and listen to the answer. "It's my partner's car and she's at work" can be fine. "I'm selling it for a mate" with no way to reach the mate is not.

Pay last, and pay with a paper trail

Here's the order I'd stick to, every time:

  1. Check the reg and MOT history before you travel.
  2. View at the keeper's address and do the VIN and log book checks above.
  3. Run a history check for finance and write-off records.
  4. Only then pay, standing next to the car.

How you pay matters too. If you're buying from a trader, putting even part of the price on a credit card can give you Section 75 protection on cars between £100 and £30,000. With a private seller it's usually a bank transfer, so pay attention when your banking app runs Confirmation of Payee. If the account name doesn't match the person in front of you, stop and ask why.

Then write a simple receipt: date, price, both names and addresses, the reg and the mileage, signed by you both. Keep the bank record with it. Our guide on paying for a used car safely compares cash, cards, transfers and finance side by side.

The takeaway

The V5C is a great tool for catching mismatches and a terrible tool for proving ownership. Use it to check the VIN, the reg and the paper, then get proof of ownership and a finance check from somewhere else. Pay last, get a receipt, and leave with the keys and the new keeper slip.

Have you ever had a log book that didn't quite add up? I'd love to hear what tipped you off.