The four write-off categories
An insurer writes a car off when it decides not to repair it, either because it is unsafe or because repair costs too much against the car's value. Since October 2017 there are four categories:
- Cat A: scrap only. The whole car must be crushed and no parts reused. It can never return to the road.
- Cat B: break for parts. The body shell must be crushed, but undamaged parts can be reused on other cars. It can never return to the road.
- Cat S: structural damage. The car can be repaired and returned to the road.
- Cat N: non-structural damage, for example cosmetic or electrical. The car can be repaired and returned to the road.
What the write-off check shows
The report reads the insurance industry's write-off register and shows each record against the registration: the category, the date of the loss, and the type and location of damage where the insurer recorded it. A car with no record gets a clear pass.
Cars written off before October 2017 show the older categories C and D, which broadly correspond to S and N.
Should you buy a Cat S or Cat N car?
It can be a sensible buy at the right price, as long as you know. A repaired Cat S or Cat N car is legal to drive and sell. It will usually be worth less than the same car with no record, some insurers charge more or decline to cover it, and it will be harder to sell on.
What matters is the quality of the repair. Ask for the repair invoices and photographs of the damage, and for a Cat S car consider an independent inspection, because the damage was to the structure.
Sellers have to tell you
A dealer must tell you about a write-off record it knows about, or ought to know about, before you buy. A private seller must not describe the car inaccurately, but is not obliged to volunteer its history, so asking the question and running the check is down to you.
When a Cat S car is kept and repaired, DVLA has to issue a replacement V5C log book. A Cat N car keeps its existing V5C, so the paperwork alone will not reveal the record.
What a write-off check cannot show
Only damage that went through an insurer as a total loss is recorded. A car repaired privately after an accident, or repaired by an insurer without being written off, has no write-off record. Uneven panel gaps, mismatched paint and fresh underseal are the signs to look for in person.