Cat C, D, N and S explained: insurance write-off categories

Insurance write-off categories tell you why an insurer decided a car was not worth repairing, and how badly it was damaged. Two of the four you will see are current, and two are historic markers that still appear on older cars. Knowing which is which is the difference between reading a car’s history correctly and misreading it.

The categories changed in October 2017

Before 1 October 2017 the repairable categories were Cat C and Cat D. From that date they were replaced by Cat S and Cat N. Nothing was reclassified retrospectively, so a car written off in 2015 still carries its Cat C or Cat D marker permanently, and a car written off since then carries S or N.

This is the single most misunderstood thing about write-off categories. If a seller tells you Cat C and Cat D no longer exist, they are half right: no new car gets one, but the old markers stay on the record for the life of the vehicle.

What Cat S means

Cat S means the car suffered structural damage and was repairable. Structural means the chassis, the crumple zones or another part of the shell designed to absorb impact, rather than a bolt-on panel.

A well-repaired Cat S car can be perfectly safe, but the quality of the repair is everything, and you cannot judge it from photographs. If you are looking at one, a professional inspection is not optional. Cat S replaced the old Cat C.

What Cat N means

Cat N means the damage was non-structural. That covers panels, lights, bumpers, interiors and, in a lot of cases, mechanical or electrical damage that simply cost more to put right than the car was worth.

Non-structural does not mean trivial. A Cat N marker can sit on a car with significant electrical or water damage, and water damage in particular can cause faults for years afterwards. Cat N replaced the old Cat D.

What Cat A and Cat B mean

Cat A means scrap only. The whole vehicle must be crushed, and not even the parts may be reused. Cat B means the shell must be crushed, though serviceable parts can be removed and sold on.

Neither category may legally return to the road. If you are offered a car described as Cat A or Cat B, walk away: it should not be for sale as a car at all.

What the older Cat C and Cat D markers tell you

Read them as the older equivalents of S and N. Cat C indicated repairable damage where the repair cost exceeded the car’s value, which in practice usually meant structural damage. Cat D indicated lighter damage that the insurer still chose not to fund.

Because the old system keyed on repair cost rather than damage type, the mapping is not perfect. A Cat D marker is not a guarantee that nothing structural was touched. On any pre-2017 write-off, treat the category as a prompt to inspect rather than an answer.

Does a write-off marker matter when buying?

It affects value, insurability and resale, and none of that is a reason to rule a car out on its own. A recorded, properly repaired write-off sold at a fair discount can be good value. The problems come from repairs done badly, or from a marker the seller did not disclose.

Expect a meaningful discount against an equivalent car with clean history, confirm your insurer will cover it before you commit, and accept that you will face the same conversation when you come to sell.

How to check whether a car has been written off

Write-off markers sit on the insurance industry’s own database, not on DVLA’s or DVSA’s, so a check built on official government data alone will not show one. Honest Car Check runs on DVLA and DVSA data, which means it gives you identity, tax, the full MOT history, mileage and recall status, and it does not report write-off markers.

For a write-off check specifically, you need a provider with an insurance-database feed. Being straight about that is more useful to you than implying we cover something we do not. Use our free check for the MOT and mileage picture, and buy a write-off check separately if the car’s history gives you reason to.