Cat S vs Cat N summary: Cat S means the car had structural damage, while Cat N means non-structural damage; repaired write-off cars can be safe, but only if the repair quality and inspection history check out. Here we answer, what written-off means? If you need further background.
Run a Total Car Check Gold Check at totalcarcheck.co.uk to see if any UK registered vehicle has previously been written off.
What’s the difference between Cat S and Cat N?
Cat S = structural damage; Cat N = non-structural damage.
Cat S (formerly Cat C) is used when an insurer has written the car off due to damage to structural parts of the vehicle (think chassis, crumple zones, pillars, floorpan, structural rails). Cat N (formerly Cat D) is used for non-structural damage, like panels, electrics, interior, trim, and sometimes mechanical components that don’t form part of the vehicle’s structural integrity. See our ultimate write-off guide.
What counts as “structural” damage in Cat S?
If it affects the car’s load-bearing/safety structure, it’s structural.
Structural areas typically include the chassis/monocoque shell, crumple zones, roof rails, A/B/C pillars, floor structure, and areas that protect occupants in a crash. Even if a car looks fine cosmetically, underlying structural repairs can be complex and must be done correctly.
What counts as “non-structural” damage in Cat N?
Damage that doesn’t affect the vehicle’s core safety structure is Cat N.
Cat N can cover expensive repairs where the structure is intact—examples include wiring looms, ECUs, sensors, suspension components, engine ancillaries, doors/wings/bonnet, and cosmetic damage. A car can be Cat N because the repair cost (and hire car costs) made it uneconomical for the insurer—not necessarily because the damage was severe.
Does Cat N always mean “minor damage”?
No—Cat N can still be serious or expensive.
“Non-structural” doesn’t automatically mean “light.” Modern cars can rack up big bills from airbag deployment, ADAS sensor replacements, complex electronics, and labour.
Which is “worse”: Cat S or Cat N?
Cat S is usually higher risk than Cat N because the structure was involved.
Structural repairs affect how the vehicle behaves in a crash and how it tracks/alines. That doesn’t mean every Cat S is unsafe—but it does mean you should be more cautious and more thorough with checks.
Will Cat S or Cat N show on a vehicle history check?
Yes—insurance write-off categories are typically recorded and can be checked. If a vehicle is in an accident and a claim is made that involves a damaged car then the insurer will record the write-off on the central Vehicle Salvage and Theft Database (formerly MIAFTR). This data is what Total Car Check and other vehicle history check providers source from to notify car buyers of any write-off history.
If you’re buying, always run a Total Car Check and verify the category, dates, and any supporting records before committing.
Are repaired write-off cars safe?
They can be safe if repaired to a high standard and properly inspected—but safety depends on repair quality, not the category label.
A well-repaired write-off with evidence, correct parts, and good alignment can be perfectly usable; a poorly repaired one can be dangerous even if it drives “okay.”
Are Cat S repaired cars safe?
They can be safe, but only if structural repairs were done correctly and verified.
Because Cat S involves the structure, the key risks are hidden: incorrect welding, poor jig alignment, substandard parts, corrosion, and compromised crash performance. You want strong documentation and a professional inspection.
Are Cat N repaired cars safe?
Often yes, but you must confirm there’s no hidden structural damage and that safety systems work.
Cat N cars may have had electrical or mechanical damage. The biggest risks usually are:- incomplete repairs, warning lights masked, or ADAS/airbag systems not recalibrated.
Do repaired write-offs need a special inspection to go back on the road in the UK?
They can be returned to the road if roadworthy, but there isn’t a single mandatory “write-off safety certificate” that guarantees repair quality.
In practice, the burden is on the buyer to verify repairs. That’s why evidence and independent inspections matter.
Are written-off cars worth less than equivalent cars with no write-off history?
Yes—written-off (Cat S/Cat N) cars are usually worth less than equivalent non-category cars, even after professional repairs.
That’s because the write-off marker reduces buyer demand, narrows finance/insurance options for some people, and adds perceived risk—so the market typically prices that in.
How much less is a Cat S or Cat N car worth?
There’s no fixed percentage, but Cat cars commonly sell at a noticeable discount versus clean-history equivalents.
The discount varies based on category, repair quality, evidence, mileage, age, desirability, and how easy it is to verify what happened. Cat S often commands a larger discount than Cat N because structural damage carries more risk in buyers’ minds.
Why does the value drop if it’s been repaired?
Because the history doesn’t disappear—future buyers still see the write-off category.
Even excellent repairs don’t remove the marker, and many buyers prefer to avoid any uncertainty. That lower demand tends to translate into a lower resale price.
Is a Cat N car always worth more than a Cat S car?
Usually yes, but not always—condition and proof matter.
A Cat N with poor electrical repairs and missing ADAS calibrations can be a worse buy than a well-documented Cat S repaired by a reputable specialist. Buyers pay for confidence as much as the category.
Can a written-off car ever be “worth it” financially?
Yes—if the discount is big enough and the repairs are well documented, a CAT car can be good value.
If you plan to keep the car for years, the lower purchase price can outweigh the lower resale value—provided you’re comfortable with the category history and you’ve verified the repair quality.
Will a write-off affect trade-in or part-exchange offers?
Often yes—many dealers will still take category cars, but offers can be lower and some dealers won’t stock them.
Dealers price in the extra time needed to sell the car, plus the smaller pool of buyers.
Does a write-off history affect car finance?
Sometimes—some lenders are cautious with written-off cars, especially if evidence is limited.
It’s not impossible, but it can reduce options or change terms.
What should I check before paying for a category car?
You should only pay a smaller discount if the proof is strong. Look for:
- Clear confirmation of Cat S vs Cat N
- Photos and invoices showing what was damaged and how it was fixed
- Independent inspection (especially for Cat S)
- Evidence that airbags/ADAS systems are functioning and calibrated (where applicable)
- A price that still reflects the permanent history marker
One-sentence buyer rule of thumb
If the price isn’t meaningfully lower than a clean-history equivalent, you’re taking extra risk for little reward.
Why do insurers write cars off if they can be repaired?
Because it’s not just damage—it’s total cost (repair, parts, labour, hire car, admin) versus the car’s value.
Even fixable cars can be written off if repair costs exceed an insurer’s threshold, even car parts lead times make hire car costs huge.
Can a Cat S or Cat N car be insured?
Yes, many can be insured, but you may have fewer insurers to choose from and premiums can be higher.
Some insurers ask more questions; others may restrict cover types.
Should I buy a repaired write-off?
Only if the price reflects the category and you can verify repair quality thoroughly.
A category car can be a smart buy if the discount is meaningful and the evidence is excellent.
What to check before buying a Cat S or Cat N car
- Check the history with Total Car Check at totalcarcheck.co.uk
- Confirm repair evidence – invoices detailing work undertaken by garages and;
- Get an independent inspection—especially on Cat S. Use firms like the AA and RAC who can run thorough physical checks on the vehicle and provide an assessment report.
