Should You Buy a Cat S or Cat N Car?

If you are looking at a used car and the price seems too good to be true, there is a chance it is a Cat S or Cat N write-off. These cars have been damaged and repaired, and they can be bought legally, but the decision to buy one is not straightforward. This guide walks through the real costs, risks, and questions you need to answer before handing over any money.

What exactly are Cat S and Cat N cars?

In the UK, insurers categorise damaged vehicles using the following letters:

• Cat A – scrap only; the car must be crushed and nothing can be reused.
• Cat B – the body shell must be crushed, but some parts can be sold.
• Cat S – structural damage, such as the chassis or suspension mounting points. The car can be repaired and returned to the road.
• Cat N – non-structural damage, such as panels, lights, or bumpers. The car can be repaired and returned to the road.

Both Cat S and Cat N cars can be legally driven once they have been repaired and pass an MOT. The key difference is whether the damage affected the structure of the vehicle. For a full breakdown of the categories, see our write-off check guide.

How much do you actually save?

The main appeal of a Cat S or Cat N car is the lower purchase price. As a rough guide, these cars typically sell for 20–40% less than an equivalent unrecorded car. On a £10,000 car, that could mean a saving of £2,000 to £4,000. On a £3,000 car, the saving might be only £600 to £1,200.

But the saving is not pure profit. You need to factor in:

• Higher insurance premiums – many insurers charge more for a previously written-off car, and some refuse cover altogether.
• Reduced resale value – when you come to sell, you will face the same 20–40% discount that you benefited from.
• Potential repair costs – if the previous repair was poor, you may need to spend money to fix issues.
• Difficulty financing – some lenders will not offer finance on a Cat S or Cat N car.

Work out the total cost of ownership over the time you plan to keep the car. If you keep it for five years and the resale loss is spread over that period, the saving may be worthwhile. If you plan to sell within a year, the discount will hit you immediately.

How does a Cat S or Cat N affect insurance?

Insurance is often the biggest hidden cost. Some insurers will not cover a Cat S or Cat N car at all. Others will offer cover but at a higher premium, sometimes 10–30% more than an equivalent unrecorded car. You must tell the insurer about the car's history – failing to do so could invalidate your policy.

If you are buying a Cat S or Cat N car, get a quote before you commit. Use a comparison site and enter the registration number, then check the box that says the car has been previously written off. If you cannot get a quote at a reasonable price, the saving on the purchase price will quickly disappear.

How do you judge the quality of the repair?

The quality of the repair is the single most important factor. A well-repaired Cat N car can be indistinguishable from an unrecorded car. A poorly repaired Cat S car can be dangerous.

Before viewing the car, ask the seller for the following:

• The name of the garage that carried out the repair.
• An itemised invoice showing what was replaced and the labour cost.
• Any photographs of the damage before the repair.
• The V5C logbook – check that the seller is the registered keeper and that the car has not been through multiple owners since the repair.

When you view the car, look for:

• Uneven panel gaps – a sign of poor alignment.
• Different shades of paint between panels – a sign of a respray.
• Welding marks under the bonnet or in the boot – check the seams are neat and consistent.
• Tyres that wear unevenly – this can indicate a misaligned chassis.

If you are not confident in your own ability to judge, pay a mechanic to inspect the car. An independent inspection costs £100–£200, which is a small price compared to the potential cost of a hidden structural fault.

What should you ask for in writing?

Before you buy, get the following in writing from the seller:

• The exact category (Cat S or Cat N) and the date it was recorded.
• The name and address of the insurer that wrote it off.
• The name of the repairer and a copy of the invoice.
• A statement that the car is roadworthy and has passed an MOT since the repair.
• Any warranty – some dealers offer a short warranty on Cat S and Cat N cars, but private sellers rarely do.

If the seller is reluctant to provide any of this, walk away. A legitimate seller will have nothing to hide.

When is a Cat N a low-risk buy?

A Cat N car can be a sensible purchase if the damage was truly cosmetic. Common examples include:

• A rear bumper that was cracked in a low-speed shunt.
• A wing that was dented and replaced.
• A bonnet that was scratched or dented.

If the repair was done properly with new parts, and the car has a clean MOT, the risk is relatively low. The main downside is the reduced resale value and the insurance premium. If you plan to keep the car for several years and you are not bothered about the history, a Cat N can offer good value.

When should you walk away entirely?

There are some situations where you should not buy a Cat S or Cat N car, no matter how cheap it is:

• You need finance. Many lenders will not offer HP or PCP on a previously written-off car. If you need a loan, check with your bank or lender first.
• You are buying for a young driver. Insurance for a young driver is already expensive. Adding a Cat S or Cat N history could make it unaffordable.
• You cannot inspect the car properly. If you are buying sight unseen from an auction or a distant seller, the risk is too high.
• The seller cannot provide paperwork. No invoice, no photos, no repairer name – walk away.
• The car is Cat S and the repair looks DIY. Structural repairs require specialist equipment and training. A DIY repair is unlikely to be safe.

Who should never buy a Cat S or Cat N car?

If you fall into any of the following groups, a Cat S or Cat N car is probably not for you:

• First-time buyers – you may not have the experience to spot a poor repair.
• People who need a reliable daily driver – a poorly repaired car could leave you stranded.
• People who plan to sell within two years – the resale loss will outweigh the initial saving.
• People who are risk-averse – even a well-repaired Cat S car carries a stigma that can affect insurance and resale.

If you are experienced, have a mechanic to inspect the car, and plan to keep it for a long time, a Cat S or Cat N car can be a way to get a better car for less money. But go in with your eyes open. Always run a write-off check before you buy, and if anything feels off, trust your instinct and walk away.