The price on the windscreen is only the start of what a used car costs you. Plenty of buyers stretch their budget to the last pound on the purchase, then get caught out by the running costs that arrive month after month afterwards. A cheap car to buy can be an expensive car to own, and vice versa. Working out the true cost of keeping a car on the road, before you commit, is the difference between a comfortable purchase and a financial squeeze.

This guide breaks down the main running costs of a used car in the UK: road tax, the MOT, insurance, servicing and repairs, fuel and depreciation. None of these should be a surprise on the day you become the keeper. Do the sums first, and you can buy the car you can genuinely afford to run, not just the one you can afford to buy.

Road tax (Vehicle Excise Duty)

Every car on a UK road needs to be taxed, unless it is declared off the road with a SORN. What you pay depends on the car, and the tax rules have shifted over the years, so the amount is heavily tied to when the car was first registered and its emissions or fuel type. Older, higher-emitting cars can carry a hefty annual tax bill, while some cars sit in much cheaper bands.

Before you buy, use the free Check vehicle tax tool on GOV.UK to confirm the car’s status, and check what the annual rate will actually be for that specific vehicle. Do not assume a tax figure from memory, because the bands and rules change. A car that looks like a bargain can quietly cost a few hundred pounds a year just to tax.

The MOT test

From its third birthday, a car needs a valid MOT every year to be legal on the road. The test itself is capped: a garage cannot charge you more than the maximum fee of £54.85 for a standard car’s MOT, though many charge less to win your custom. Cars over 40 years old are generally exempt.

The MOT cost that really matters is not the test fee, it is what the test finds. A car that scrapes through with a long list of advisories is warning you about bills to come. This is exactly why the free Check MOT history tool on GOV.UK is so valuable before you buy: it shows every test since 2005, the advisories and failures, and the recorded mileage each time. A history full of repeated advisories tells you the car has been run on the cheap and will keep asking for money. We show how to read it in how to check a used car in the UK.

Insurance

Insurance is often the biggest running cost of all, especially for younger drivers, and it varies enormously from car to car. Before you fall for a particular model, get a few real quotes for it. The premium depends on the car’s insurance group, its value, your age and history, where you live and how you use it.

One point that catches used-car buyers out: a car recorded as a write-off can be more expensive or trickier to insure, even when it has been properly repaired. Under the UK categories, a Category S (structural) or Category N (non-structural) car is legal to buy and drive once repaired, but it can affect your premium and your resale value. That is one more reason to run a paid history check that reveals write-off status, which the free GOV.UK checks do not show. We compare the options in free GOV.UK checks vs a paid HPI check.

Servicing and repairs

Every car needs servicing, and every used car will eventually need repairs. Two things drive this cost.

The model. Common cars like the Ford Focus are cheap to run because parts are plentiful and every garage knows them. More unusual or premium cars can cost far more for the same job. Our used Ford Focus buyer’s guide is an example of matching the car to a sensible running budget.
The individual car’s condition. A neglected example arrives with a queue of jobs waiting. This is where a proper pre-purchase inspection pays for itself many times over, because the faults you find now are either money off the price or money you spend later.

Big-ticket items to think about include tyres, brakes, clutches, cambelts and, on diesels, the emissions kit. Budget for a service soon after purchase unless the car comes with fresh, documented history.

Fuel or charging

Fuel is the running cost you feel most often. Match the car to your driving. A thirsty petrol or a large engine punishes you on every trip if you cover big miles, while a diesel only rewards you if you genuinely do the motorway mileage to justify it. An electric car can be dramatically cheaper to run if you can charge at home, though the maths changes if you rely on public rapid charging. We cover the electric side in buying a used electric car in the UK.

Depreciation, the cost you do not see

The quietest and often largest cost of all is depreciation: the value the car loses while you own it. You do not get a bill for it, but you feel it the day you sell. Buying a car that holds its value well, keeping the service history intact and looking after it all reduce the sting. It is also why buying a car with a hidden problem hurts twice, once when it breaks and again when you come to sell a car with a patchy record.

Add it all up before you buy

The honest way to compare two cars is on total cost of ownership, not sticker price. Add tax, insurance, an MOT, expected servicing, fuel and likely depreciation, and the cheaper car to buy is often not the cheaper car to own. When you have that full picture, you also have leverage: known upcoming costs are legitimate reasons to negotiate, as we explain in how to haggle a used car price in the UK.

Know the costs before you commit, with MotoPPI

Running costs start with buying the right car in the first place. MotoPPI checks a car’s history across more than 20 databases, gives you a model-specific inspection checklist, estimates likely repair costs so you can budget honestly, and hands you the arguments to negotiate. It turns hidden future bills into information you can act on before you pay. Your first check is free, on the App Store now.

Download MotoPPI on the App Store and check your first car for free.

Frequently asked questions

How much does an MOT cost in the UK?

The MOT test fee is capped at a maximum of £54.85 for a standard car, and many garages charge less. Cars over 40 years old are generally exempt. The bigger cost is whatever the test finds, so check the free GOV.UK MOT history before you buy.

How do I find out the road tax on a used car?

Use the free Check vehicle tax tool on GOV.UK to confirm the car’s current status, and check the annual rate for that specific vehicle. Tax depends heavily on when the car was registered and its emissions or fuel type, and the rules change, so verify the figure rather than assuming.

Does a write-off affect insurance and running costs?

It can. A Category S or N car is legal to buy and drive once properly repaired, but it may be harder or dearer to insure and worth less when you sell. The free GOV.UK checks do not show write-off status, so a paid history check is worth it.

What is the biggest hidden running cost of a used car?

Depreciation. You never receive a bill for it, but it is often the largest cost of ownership and you feel it when you sell. Buying a car with a clean history that holds its value well is the best defence.

Running Costs of a Used Car in the UK: Tax, MOT and Insurance