Can you modify a financed car?

This is because the lender owns the vehicle until your agreement ends. You're the registered keeper, but not the legal owner. That means any changes (like new wheels, a wrap, or a sound system) could break the terms of your contract.

Once you've finished all your payments, you’re free to customise the car however you like. You can do anything. And if you're unsure, it's always best to ask the finance company first.

Why don't companies want you to modify a car on finance?

Finance companies expect the car to stay in its original condition. That’s because they still own it until you finish your payments. They need the car to hold its value so it can be easily resold if returned.

If you change the engine, bodywork, or interior, it could reduce the car’s value or make it harder to sell. And if damage happens during a modification, you’ll likely be responsible for the repairs. Keeping the car as it came helps avoid fees, contract issues, or unexpected costs later.

What do car finance companies consider to be modifications?

A modification is anything that changes how the car looks, works, or feels compared to when you first got it.

Finance companies want the car to stay in its original condition. That way, it keeps its resale value and stays easy to inspect, return, or sell.

Here are some common types of modifications finance companies usually flag:

• Performance upgrades – You might swap out the exhaust, upgrade the engine, or fit a different gearbox.
• Cosmetic changes – A new paint job, window tints, custom wheels, or updated interior trim all count.
• Towing equipment – Adding a tow bar might seem simple, but it still changes how the car functions and what it’s used for.
• Entertainment systems – Screens, speakers, or a new sound system might involve rewiring parts of the car, which can damage its original setup.

Even if the change seems small, the finance company still has the final say. And if they haven’t approved it, it could lead to extra costs or a breach of contract.

Can you modify a car on HP?

You can modify a car on hire purchase (HP), but only with permission from the finance company.

With HP, you don’t legally own the car until you've made the final payment. Until then, the lender holds ownership, and you're expected to follow their rules. Some agreements may not mention modifications at all. If that’s the case, you still need to contact the finance company and ask.

If they agree to the changes, ask for written confirmation before you start. Don’t rush into swapping wheels or upgrading the stereo without it. And if they say no or don’t reply in writing, it’s safer to wait until the car is fully yours.

Can you modify a car on PCP?

You can’t usually modify a car on personal contract purchase (PCP).

With PCP, most people return the car at the end of the agreement instead of buying it. That’s why lenders expect it to come back in its original condition. Any major change (like repainting, body kits, or engine upgrades) could reduce the car’s value and lead to extra charges.

You must speak to the finance company before making any changes. It’s rare for them to allow major modifications, but if they do give permission, make sure you get it in writing. Without clear approval, it’s best to leave the car as it is.

What modifications can you do to a financed car?

You can add small, non-permanent items to a financed car, but you need to stay within limits.

Simple accessories like seat covers, phone holders, dash cams, or air fresheners are usually fine. They don’t change how the car looks or performs in a lasting way, and you can remove them without leaving a mark. Most finance companies won’t worry about these, because they don’t affect the car’s condition or resale value.

But once you start replacing parts (even something like tyres or wiper blades) you need to stay careful. Always use approved, good-quality replacements. Cheap parts can wear out fast or cause damage, and if that happens, the cost falls on you. And finance companies won’t cover that. They care about keeping the car in the best possible condition.

Can I modify my car on finance if it increases the value?

Of course you cannot. Boosting the car’s value doesn’t mean you can modify it without permission.

Even if your changes improve performance or style, the finance company may still reject them. They usually care more about keeping the car in its original condition than about added value. And most lenders aren't interested in upgrades, they want a car that’s easy to sell.

Performance upgrades or cosmetic changes can also move the car into a different category, which might make it harder to resell. So even with good intentions, your changes could work against you.

If your contract restricts modifications, your argument won’t matter. Always get written approval first, even if you think the upgrade is an improvement.

What to do before modifications?

Even if you’ve planned everything, you need to take two important steps first. Skipping them could lead to serious problems later. So before you make any changes:

Analyse your finance agreement

Your finance agreement tells you exactly what you can and can’t do with the car.

If it clearly says no modifications are allowed, you won’t have any legal ground to challenge it. Breaking those rules could lead to penalties and no lawyer can help if the contract is clear.

If you’ve lost the agreement, don’t do anything until you get a copy. You can always ask your finance provider to send one. It’s a good idea to print a copy and keep it somewhere safe.

Text or call your finance company

Always speak to your finance company before making any major changes to the car.

Small things like phone holders aren’t a problem. But anything bigger (like bodywork, engine upgrades, or tech installs) needs written permission. A quick call or text is a good way to start the conversation, but a verbal “yes” won’t protect you if something goes wrong.

Ask for written confirmation of their approval. That way, if there’s ever a dispute, you have clear proof. It could save you stress, money, and legal trouble later.

What happens if you modify a financed car?

If you have written permission from the finance company, you’re in the clear.

But if you make changes without consent, you could face serious consequences. The finance company may demand full payment and expect you to settle the remaining balance within 14 days. That means you’ll need to buy the car outright immediately.

And if you refuse or can’t pay, the lender may take further action, including ending your agreement early. It’s not worth the risk, so always get written approval first.

What happens if you have to return your modified car to the finance company?

You won’t get anything back for the upgrades.

If you return a modified car, the finance company will sell it usually at auction. And most of the time, modifications don’t help. They often lower the resale value because buyers prefer cars in their original condition. If the car sells for less than what you owe, you’ll need to cover the difference.

Let’s say the car was worth £15,000, but it only sells for £13,000. You’d be expected to pay the £2,000 shortfall. But if the car sells for more, the finance company keeps the full amount. You won’t owe anything more, but you won’t see a penny from the sale either.

So any money you’ve spent on modifications is likely gone for good.

If you can return a modified car to its original state, is it okay to modify a financed car?

Even if you can reverse the changes, it’s still risky to modify a financed car.

You might be able to swap the engine or restore the original parts later, but that takes time and money. If the lender needs to inspect or value the car suddenly, you won’t have time to undo the work.

And if the car’s in an accident before you put it back to normal, you’re in trouble. The lender will notice the changes, and that could void your agreement. Even minor mods can lower the car’s value. If the damage is serious, you could be forced to pay off the full remaining balance straight away.

You’ll own the car, but only because you’ve had to buy it out. And that’s a costly way to become the legal owner.

So yes, reversing changes is possible. But it’s still a gamble. Stick to the rules and play it safe.

How does the car program work if I want to keep it at the end of the agreement?

Once you make the final payment, the car is yours, and you can modify it however you like.

At that point, the finance company has no say in what you do. Any upgrades, tweaks, or cosmetic changes are completely your business. You’re now the legal owner, so you can finally personalise the car without restrictions.

But until that payment is made, the risks still apply. If you modify the car too early and something goes wrong, you could face charges or be forced to buy the car outright. It’s always safer to wait.

So hold off on big changes until the car is officially yours, and then enjoy making it your own.

Contact our brokers for consultation

If you’re unsure about what you can do, speak to one of our brokers. We’ll explain your options, check your agreement, and help you avoid any costly mistakes.

It’s better to ask than to risk breaking the rules. Give us a call when you need clear, honest advice.