The Complete Guide to Buying and Selling a Used Car in the UK
Key takeaways
- Vehicle tax is not transferred to you when you buy a vehicle: you must tax it (or declare it off the road with a SORN) before you drive it (GOV.UK)
- A car's free MOT history shows the mileage at every test since 2005, which helps you spot a mileage that doesn't add up
- A car that's a few years old has usually already had its steepest drop in value, but check actual prices for the model you want
- Vehicles built before 1 January 1986 can stop paying vehicle tax from 1 April 2026, but you must apply for the exemption. The MOT exemption applies to vehicles built or first registered over 40 years ago with no substantial changes
- To keep a private plate when you sell, you take it off the car and put it on retention with the DVLA (you get a V778 document)
- Check for outstanding finance before you buy privately
Buying or selling a used car involves checks, paperwork and rules that don't come up elsewhere in car ownership, and mistakes can be costly. This guide walks through the process from both sides, with the relevant calculator at each stage.
1Checking a used car before you buy
A very useful free check is the car's MOT history on GOV.UK, which needs only the registration number. For each test it shows whether the car passed or failed, the mileage recorded and when the next MOT is due, and for tests in England, Scotland and Wales it also shows which parts failed or had minor problems. For cars, results go back to tests since 2005. A genuine mileage history climbs steadily from test to test; a mileage that goes backwards or stalls without explanation is a red flag for odometer tampering ("clocking").
In person, check the tyres, the bodywork and the service history, and take the car for a proper test drive.
🛞 Use the Tyre Tread Depth Checker → 🔧 Use the MOT Due Date Calculator →
2Depreciation from the buyer's side
New cars usually lose value fastest in their first years. If you buy a car that is a few years old, the first owner has already absorbed much of that fall, so you buy into a flatter part of the curve. How much a model loses varies widely, so compare recent sale prices for the exact model, age and mileage, rather than relying on a rule of thumb.
📉 Use the Car Depreciation Calculator →3Financing a used car
HP and PCP are both available on used cars, though terms can differ from new-car finance. With HP you own the car once the final payment is made. With PCP the monthly payments are usually lower, but you only own the car if you pay the final optional payment (or you can hand it back or part-exchange, subject to the agreement's terms). Compare the total amount payable, the APR and any mileage limits, not just the monthly figure.
💳 Use the PCP & HP Car Finance Calculator →Check for outstanding finance before buying privately. If the seller still owes money on the car, that can cause problems for you as the buyer. A paid vehicle history check can show whether finance is recorded against the car. Do this before you hand over any money.
4Road tax on a used car — the rule everyone gets wrong
Vehicle tax is not transferred to you when you buy a vehicle (GOV.UK). When the seller tells the DVLA they have sold it, their tax is cancelled and they can get a refund for any full months left. As the buyer, you must tax the vehicle yourself before you drive it, or declare it off the road with a SORN.
Don't drive a newly bought car home assuming it is already taxed. Tax has to be in place in your name before you drive it, and driving an untaxed vehicle can lead to penalties.
5Buying a classic or older car
Older vehicles can qualify for two separate exemptions, with different rules:
- Vehicle tax: vehicles built before 1 January 1986 can stop paying vehicle tax from 1 April 2026 (if the build date is unknown, registered before 8 January 1986). You must apply for the exemption, called the "historic tax class". The cut-off moves forward over time, so check GOV.UK for the date that applies to your car
- MOT: you don't need an MOT if the vehicle was built or first registered more than 40 years ago and has had no substantial changes, such as replacing the chassis, body, axles or engine in a way that changes how it works. The car must still be kept roadworthy
An exemption is not the same as having no rules: a vehicle in a dangerous condition can still lead to a fine of up to £2,500 and 3 penalty points.
6Number plates when buying or selling
If a seller wants to keep a private number, they must take it off the car and put it on retention (or assign it to another vehicle) with the DVLA. They then receive a V778 retention document as proof that they still hold the number. If the number is kept without being assigned, the right to use it must be renewed every 10 years.
🔢 Use the Number Plate Personalisation Cost Calculator →As a buyer, ask the seller whether the registration on the advert will stay with the car, and agree it in writing before you pay. If you are the seller, don't share a scan or photo of your V750 or V778 online, because someone could use it to move your number to another vehicle.
7The paperwork: transferring ownership
The simplest way to tell the DVLA about a sale is the online service, where the seller changes the registered keeper and the log book (V5C) is sent to the new keeper. If you don't have the V5C, you can write to the DVLA with the registration number, make and model, the exact sale date and the new keeper's name and address. A buyer without a log book can apply for a vehicle registration certificate using form V62. Telling the DVLA also cancels the seller's vehicle tax.
Because the registered keeper is the person the DVLA holds responsible, sellers should tell the DVLA straight away and keep a record of the sale (date, price and buyer's details). The postal route works through the sections of the V5C itself, so follow the instructions printed in your V5C.
- Selling: tell the DVLA online, keep a dated record of the sale, and cancel any insurance only after the keeper change is done
- Buying: check the V5C matches the car (registration, VIN/chassis number and keeper details), check it doesn't look altered, tax the vehicle before you drive it, and make sure the V5C in your name arrives
8Common used car scams and red flags
- Cloned plates: a genuine vehicle's registration copied onto a different car. Check that the VIN matches the V5C, and be wary if either looks altered
- Mileage clocking: compare the MOT history mileage and service book stamps with the odometer. Unexplained inconsistencies are a serious red flag
- Pressure to pay in cash with no paperwork: a legitimate seller should be happy with a proper record of the sale and the DVLA change of keeper
- Undisclosed outstanding finance: check independently rather than taking the seller's word for it
- Meeting away from the address on the V5C: not always suspicious, but be cautious if combined with other red flags
Buyer's checklist
- MOT history checked for mileage consistency and past advisories
- Tyres and condition checked in person, not just from photos
- Outstanding finance checked before paying
- V5C checked for consistency: VIN, keeper details, no signs of alteration
- Vehicle tax arranged in your own name before you drive
- For an older car, checked whether it qualifies for the historic tax class or MOT exemption
- Agreed in writing whether the registration stays with the car
Frequently asked questions
Does road tax transfer when you buy a used car?
No. GOV.UK says the tax is not transferred to you when you buy the vehicle. The seller's tax is cancelled when they tell the DVLA, and they can claim a refund for full remaining months. You must tax the vehicle before you drive it, or declare it off the road with a SORN.
How can I check if a used car has been clocked?
Check its free MOT history on GOV.UK, which shows the recorded mileage at each test (for cars, tests since 2005). A genuine history climbs steadily; unexplained drops or long gaps are a red flag. Compare it with the odometer and the service history.
Should I check for outstanding finance before buying a used car privately?
Yes. If the seller still owes money on the car, that can cause problems for you as the buyer. A paid vehicle history check can show whether finance is recorded against the car.
Can I keep my personalised number plate when I sell my car?
Yes. You take the number off the car and put it on retention with the DVLA (or assign it to another vehicle). You then receive a V778 retention document. It doesn't happen automatically when the car is sold.
Do I need to inform the DVLA when I sell my car?
Yes. The quickest way is the online service, where you change the registered keeper and the new keeper is sent the log book. Telling the DVLA also cancels your vehicle tax, and you can claim a refund for full remaining months.
All tools referenced in this guide
Sources
- GOV.UK — Check the MOT history of a vehicle
- GOV.UK — Selling or buying a vehicle: tell DVLA
- GOV.UK — Historic (classic) vehicles: MOT and vehicle tax
- GOV.UK — Personalised vehicle registration numbers
- GOV.UK — Vehicle tax rate tables
Prakash
Prakash is the founder and editor of UK Driving Tools. He maintains the site's calculators and guides and checks the rates and rules they use against official UK sources, such as GOV.UK, the DVLA, HMRC and Transport for London, before publishing.
Pages are drafted with the help of AI tools and then checked by the editor. He isn't a lawyer, accountant or UK-qualified adviser, so every page lists its sources and states what its calculator can't tell you. Nothing on this site is legal or financial advice.
Pages on UK Driving Tools are drafted with the help of AI tools. Before publishing, the figures and rules on each page are checked against the official source named on the page, and calculator examples are tested against the working formula. Pages are updated when rates or rules change. Our Editorial Policy explains the full process, including how to report a mistake.
Spotted a mistake or an out-of-date rate? Let us know and we'll check it against the official source.