Write-off categories explained: Cat A, B, S and N

The four categories

• Cat A (scrap): the whole car must be crushed. No parts can be taken off and reused.
• Cat B (break): the body shell must be crushed, but parts can be taken off and sold. The car can never go back on the road.
• Cat S (structural): the chassis or body structure is damaged, for example a bent frame or crumple zone. It can be properly repaired and driven again.
• Cat N (non-structural): the damage isn't to the structure (electrics, trim, panels, or a theft recovery) but cost too much for the insurer to repair. It can be repaired and driven again.

The old categories: Cat C and Cat D

Cars written off before October 2017 used different letters. Cat C and Cat D could both be repaired: Cat C cost more to fix than the car was worth, and Cat D cost less. Unlike Cat S and N, the old letters said nothing about whether the damage was structural, so check an old Cat C or D car's repairs carefully.

Buying a Cat S or Cat N car

• The category stays on the car's record for good and shows on any vehicle history check, so it will always be worth less than the same car with a clean history.
• Ask what the damage was, who repaired it and what parts were used, and get it inspected before you pay. For Cat S, a check by a body shop or an independent inspector is money well spent.
• Tell your insurer it's a write-off when you get a quote. Some charge more, and not telling them can void the cover.

Parts from written-off cars

Most cars in a breaker's yard are write-offs, often Cat B or Cat N, and the undamaged parts on them are just as good as on any other used car: a Cat N car hit in the back can have a perfect engine, gearbox and front end. Ask the seller which car the part came off and its mileage, and check the part number matches yours (how to find the right part).

Repairing a Cat S or Cat N car yourself? Used panels, lights and airbags from the same model can save a lot over new. Search by your registration to see parts that fit, or browse by make.