If you've been shopping for used cars, you may have come across vehicles advertised as "Cat N" or "Cat S" at temptingly low prices. But what do these categories mean, and should you consider buying one?
What are Insurance Write-Off Categories?
When a car is damaged and the repair cost exceeds a certain percentage of its value, insurance companies "write it off" rather than repair it. The car is then classified into one of four categories:
- Category A – Scrap only, cannot return to the road
- Category B – Body shell must be crushed, but parts can be salvaged
- Category S – Structural damage, can be repaired and returned to road
- Category N – Non-structural damage, can be repaired and returned to road
Cat S (Structural Damage) Explained
Category S replaced the old "Cat C" classification in 2017. It means the car has suffered structural damage – damage to the chassis, frame, or crumple zones.
Cat S cars can legally return to the road after repair, but:
- They must be professionally repaired
- The structural integrity must be restored
- The write-off marker is permanent on the vehicle's record
Cat N (Non-Structural Damage) Explained
Category N replaced "Cat D" and means the car has non-structural damage. This might include:
- Cosmetic damage (panels, bumpers)
- Electrical damage
- Engine damage
- Interior damage (flood damage often falls here)
Cat N sounds less serious, but don't be fooled – a car written off due to engine failure or electrical damage can be just as problematic as one with structural damage.
Should You Buy a Cat N or Cat S Car?
Potential Benefits
- Lower price – Write-offs typically sell for 20-40% less than equivalent clean cars
- May be well-repaired – Some write-offs are professionally restored to high standards
- Good for parts or projects – If you're mechanically minded
Significant Risks
- Unknown repair quality – You can't see what was done beneath panels
- Safety concerns – Poor repairs could compromise crash protection
- Insurance difficulties – Some insurers won't cover write-offs, others charge more
- Reduced resale value – The write-off marker stays forever
- Harder to sell – Many buyers avoid write-offs entirely
How to Check for Write-Off History
Write-off history doesn't appear on free DVLA checks. You need a vehicle history check that accesses insurance industry databases.
A Green Flag vehicle check will reveal:
- Whether the car has ever been written off
- The write-off category
- When it was written off
- Salvage auction history (exclusive feature)
If You Do Buy a Write-Off
If you decide to proceed with a Cat N or Cat S car:
- Get documentation – Ask for repair invoices and photos
- Have it inspected – Pay for an independent engineer's report
- Check insurance first – Confirm you can get affordable cover
- Factor in resale – Accept you'll lose more when selling
- Understand the damage – Know exactly what was damaged and how it was repaired
The Bottom Line
Cat N and Cat S write-offs can be good deals if you know what you're buying and the repairs were done properly. But they're not for everyone, and the savings come with real risks.
Always run a vehicle history check before buying any used car – especially if the price seems too good to be true. Check a car's write-off status now.
