Cat S Check: Structural Write-Off Check by Reg

Cat S stands for Category S (structural). It is a UK insurance write-off category introduced in 2017, replacing the old Cat C designation. A Cat S vehicle sustained structural damage in an accident: this means the chassis, crumple zones, sills, A/B/C pillars, or other load-bearing structural components were damaged. Cat S cars can legally return to the road after a qualifying structural repair, but the write-off marker stays on the vehicle's history permanently and must be disclosed to insurers.

Run a Carhealth vehicle history report using the car's registration plate. The report queries national insurer write-off databases and returns the write-off category (if any), the date of the write-off, and whether the car has since been returned to road. Results arrive in under 60 seconds. Free checks such as the DVLA vehicle enquiry service do not include write-off history. You need an accredited provider to access insurer records.

A Cat S car can be safe to buy and drive, provided the structural repair was carried out to a proper standard by a qualified repairer and the vehicle has been correctly inspected before returning to road. However, the key risk is that repair quality varies considerably. Always ask for the full repair history, evidence of any post-repair inspection, and details of the original damage. Budget for an independent structural inspection if you're not sure. See our full write-off category guide at /write-off-check.

A Cat S designation usually reduces a car's market value compared to an undamaged equivalent, and by more than a Cat N. The exact reduction depends on the severity of the original damage, the quality of the repair, the make and model, and current market conditions. Specialist car buyers and dealers will price Cat S cars accordingly, so if a seller is offering a Cat S car at close to market value without disclosing the history, you may be overpaying significantly.

Yes. Buying a Cat S vehicle and failing to declare its write-off history to your insurer is a form of material non-disclosure and can invalidate your insurance policy. Most insurers will ask specifically about write-off history when you apply for cover. If you make a claim and the insurer discovers undisclosed write-off history, they may refuse to pay. Always declare Cat S status and get quotes from multiple insurers before completing your purchase.

Cat S (structural) means the vehicle suffered damage to structural components such as the chassis or crumple zones. Cat N (non-structural) means the damage was limited to non-structural parts: cosmetic panels, trim, electrical systems, or non-load-bearing suspension components. Both categories allow the car to return to road after repair, and both must be declared to insurers. Cat S cars typically carry higher repair costs and a greater value reduction. See /cat-n-check for more on Category N write-offs.