Cat N Write-Off Explained: Buying, Insuring and Reselling

What Cat N actually means

Cat N (Category N) was introduced in October 2017 as part of the four-category overhaul that replaced the older Cat C and Cat D system. The N stands for "non-structural": damage to bodywork, lights, trim, infotainment, electrics, airbags or any other component that is not part of the structural shell of the car. The chassis, subframe and crumple zones are intact.

A car ends up as a Cat N usually for one of two reasons: the cost of replacement parts (a new headlight cluster and bumper assembly, for instance) exceeded the market value of an older car; or the airbags deployed in a minor collision and the cost to replace the airbag system and SRS controller pushed the numbers past the threshold. Many Cat N cars are mechanically and structurally perfect.

The marker is recorded against the registration on the Motor Insurance Anti-Fraud and Theft Register (MIAFTR) and follows the car forever, even after every visible trace of the damage has been repaired.

Typical Cat N damage types

• Front-end collision damage to bumper, lights and cooling pack, where the bonnet absorbed the impact without affecting the chassis.
• Rear-end shunt damage to bumper, boot panel and parking sensors.
• Side-impact damage to doors and exterior panels that did not deform the B-pillar or sill.
• Airbag deployment after a low-speed collision, with expensive SRS and module replacement.
• Vandalism or theft damage to interior trim, infotainment and steering column.
• Cosmetic flood damage to seats, carpets and lower door cards where the floor pan and wiring were saved.

Cat N vs the older Cat D

Cars written off before October 2017 carry Cat D for the same damage profile. Cat D is the legacy equivalent of Cat N and the two should be treated as broadly the same for buying purposes. The damage thresholds and definitions differed slightly, but the practical implications (resale value drop, insurance uplift, finance restrictions) are almost identical.

A Cat D marker on an older car can sometimes be cosmetic-only damage that would not even qualify as Cat N under current rules. If the car is well outside warranty and the price is right, Cat D can be one of the better discount opportunities on the used market.

The buying checklist

1. Run a paid history check first. The Vehicle History Check (£14.99) returns the MIAFTR record, the date the marker was applied and the insurer who recorded it.
2. Get repair documentation in writing. A professional bodyshop invoice with VAT, parts list and labour breakdown. Photos during repair are the gold standard.
3. Inspect the airbag system. Confirm the SRS warning light cycles correctly. A stuck or skipped warning light points to a deleted fault code rather than a real repair.
4. Quote insurance before you offer. A 10 to 20% uplift is normal; refusal across multiple insurers suggests serious undisclosed issues.
5. Negotiate hard. Cat N sellers sometimes price at 5 to 10% under market. That is not the right discount. Aim for at least 15%.
6. Long test drive over rough roads. Vibration through the steering wheel, brake pull, alignment drift and unusual creaks are the first signs of poor secondary repair.

Common Cat N scams

• Undisclosed marker. Private sellers are the highest-risk source. Always check yourself.
• Cloned identity. A salvaged Cat N is rebuilt onto the registration of a written-off similar vehicle. Cross-check VINs at windscreen, door pillar and chassis against the V5C.
• Marker-clearance claims. MIAFTR markers cannot be removed. Anyone offering to is committing fraud.

The bottom line

A Cat N car can be a strong buy at the right price. The structure is sound, the repair is generally straightforward, and the value discount is recoverable if you keep the car long enough. Always confirm the marker yourself, insist on repair documentation, and quote insurance before you commit money.