Understanding Write-Off Categories - Complete UK Guide to Cat A, B, S, N (2025)
Complete guide to insurance write-off categories in the UK. Learn what Cat A, B, S, and N mean, whether you should buy a Cat S or Cat N car, insurance implications, value impact, how to check write-off status, and repair quality verification.
Approximately 400,000 vehicles are written off by insurance companies in the UK every year. Many of these cars end up back on the roads - some perfectly safe after professional repairs, others dangerous death traps sold to unsuspecting buyers.
Understanding write-off categories is crucial because:
- Cat S and Cat N cars can be worth 20-40% less than clean examples
- Cat A and Cat B cars should NEVER be back on the road (but sometimes are)
- Insurance companies treat write-offs differently (higher premiums or outright refusal)
- Poorly repaired write-offs can be unsafe and cost thousands to fix properly
- Many sellers don't disclose write-off history
This comprehensive guide explains everything you need to know about UK insurance write-off categories, whether you should buy a previously written-off car, and how to protect yourself from dangerous or overpriced damaged vehicles.
What Is an Insurance Write-Off?
An insurance write-off (or total loss) occurs when an insurance company determines that:
- Repair costs exceed the vehicle's pre-accident value, OR
- Repairs are uneconomical (typically 50-70% of vehicle value), OR
- The vehicle is unsafe and cannot be repaired
What happens:
- Car is involved in accident, flood, fire, theft, or other incident
- Owner makes insurance claim
- Insurance assessor inspects damage
- If repair costs too high, car is "written off"
- Insurance company pays owner the pre-accident value
- Insurance company takes ownership of the vehicle
- Car is assigned a write-off category
- Car is registered on national write-off databases
- Car is sold at salvage auction or scrapped
Key point: Just because a car is written off doesn't mean it's unsafe. It often just means repairs would cost more than the car is worth at that moment.
Example:
- 2019 Fiesta worth £8,000
- Accident damage requiring £5,500 repairs
- Insurance company writes it off (62% of value)
- But car IS repairable and could be safe after proper repair
The UK Write-Off Categories Explained
In October 2017, the UK changed write-off categories from A, B, C, D to A, B, S, N:
Old system (pre-October 2017):
- Category A: Scrap only
- Category B: Break for parts
- Category C: Structural damage (repairable)
- Category D: Non-structural damage (repairable)
New system (post-October 2017):
- Category A: Scrap only
- Category B: Break for parts
- Category S: Structural damage (repairable)
- Category N: Non-structural damage (repairable)
Important: Cars written off before October 2017 still carry their original category (C or D).
Let's examine each category in detail:
Category A - Scrap Only (Do Not Buy)
What it means:
- Most severe damage category
- Vehicle and ALL parts must be crushed
- Cannot be repaired under any circumstances
- No parts can be salvaged for road use
- Vehicle identity must be destroyed
Typical damage:
- Total fire damage
- Severe structural collapse
- Flood damage beyond recovery
- Major collision with complete destruction
- Multiple severe impacts
Legal status:
- ILLEGAL to return to road
- All components must be destroyed
- V5C registration certificate destroyed
- DVLA notified of destruction
If you see a Cat A car for sale:
- Walk away immediately
- Report to police and DVLA
- It should not exist
- Serious safety risk
- Likely using false identity (cloned plates)
There are NO circumstances where buying a Cat A car is acceptable.
Category B - Break for Parts (Do Not Buy)
What it means:
- Extensive damage
- Body shell must be crushed
- Parts can be salvaged for other vehicles (engine, gearbox, doors, etc.)
- Vehicle itself cannot return to road
- Identity must be destroyed
Typical damage:
- Severe structural damage
- Major fire damage
- Extensive collision damage
- Chassis/frame damage beyond repair
- Safety-critical structural failure
What can be salvaged:
- Engine and gearbox (if undamaged)
- Doors, bonnet, boot
- Interior components
- Electrical components
- Wheels and tyres
- Non-structural mechanical parts
What must be destroyed:
- Body shell/chassis
- VIN plates
- V5C registration
Legal status:
- ILLEGAL for vehicle to return to road
- Body shell must be crushed
- Parts can be used in other cars
- DVLA notified
If you see a Cat B car for sale:
- Walk away immediately
- Report to police and DVLA
- Should not exist as a complete vehicle
- Extremely dangerous if somehow rebuilt
- Likely illegal reconstruction
There are NO circumstances where buying a Cat B car is acceptable.
Category S - Structural Damage (Consider Carefully)
What it means (the "S" stands for Structural):
- Damage to structural or safety-critical areas
- Repairable and can legally return to road
- Repairs must meet safety standards
- No legal requirement for inspection (but recommended)
Structural areas include:
- Chassis/frame
- Crumple zones
- Suspension mounting points
- Subframe
- Sills
- A, B, C pillars
- Roof structure
- Floor pan
Typical damage scenarios:
- Front/rear collision affecting crumple zones
- Side impact affecting pillars or sills
- Suspension damage affecting mounting points
- Structural deformation from impact
- Previous poor repairs causing structural concerns
Legal status:
- CAN be repaired and returned to road
- Must pass MOT like any other vehicle
- Remains Cat S forever (marker never removed)
- Must be declared when selling or insuring
Value impact:
- Typically worth 25-40% less than identical non-Cat S car
- £10,000 car becomes £6,000-£7,500 when Cat S
Should You Buy a Cat S Car?
Maybe - but only if ALL these conditions are met:
1. Price reflects category:
- 30-40% discount minimum
- £10,000 equivalent should be £6,000-£7,000
- Don't pay Cat N prices for Cat S car
2. Full repair documentation available:
- Detailed pre-repair damage photos
- Itemised repair invoices
- Professional repair shop used (not DIY)
- Genuine parts used (receipts proving this)
- Paint/body shop receipts
3. Professional repair quality:
- Repaired by reputable bodyshop
- Structural straightening done properly
- Proper alignment and geometry
- No evidence of poor quality work
- Photos of repair process (if available)
4. Independent inspection confirms quality:
- Pay for professional inspection (£150-£300)
- Specialist checks:
- Chassis alignment
- Suspension geometry
- Structural integrity
- Paint thickness (detecting filler)
- Previous damage extent
- Written report confirming safe repair
5. You can get insurance:
- Contact insurers BEFORE buying
- Some insurers refuse Cat S
- Others charge 10-30% premium
- Comprehensive cover may be limited
6. You understand resale implications:
- Cat S marker stays forever
- Harder to sell
- Lower resale value
- Many buyers avoid Cat S
- Finance companies may refuse to lend on Cat S
7. Damage was relatively minor:
- Front-end collision (crumple zone designed to absorb impact)
- Single impact, not multiple
- No side impact (pillar damage is serious)
- No roof or floor damage
When to AVOID Cat S Cars:
Walk away if:
- Seller didn't disclose Cat S status (dishonesty)
- No repair documentation available
- DIY repairs or unknown repair shop
- Severe damage (roof, pillars, multiple impacts)
- Suspension geometry visibly incorrect
- Paint quality poor or uneven
- Price doesn't reflect 30-40% discount
- Insurance quotes are unacceptably high
- You plan to resell within 2-3 years
- You cannot afford professional inspection
Category N - Non-Structural Damage (More Acceptable)
What it means (the "N" stands for Non-structural):
- Damage to non-structural or cosmetic areas
- NO damage to chassis, frame, or structural components
- Repairable and can return to road
- Generally less serious than Cat S
Non-structural damage includes:
- Cosmetic bodywork (dents, scratches, panels)
- Lights and glass
- Interior components
- Infotainment and electronics
- Paintwork
- Bumpers and trim
- Wheels and tyres
- Electrical systems
- Air conditioning
- Brake systems (mechanical, not mounting points)
Typical scenarios:
- Cosmetic damage from parking collision
- Hail damage (dents across panels)
- Flood damage affecting electrics
- Interior fire damage
- Theft damage (interior, broken glass, ignition)
- Vandalism
- Electrical system failure
- Multiple minor cosmetic issues adding up
Legal status:
- CAN be repaired and returned to road
- No structural inspection required
- Must pass normal MOT
- Cat N marker stays forever
- Must be declared to insurers and buyers
Value impact:
- Typically worth 15-25% less than identical non-Cat N car
- £10,000 car becomes £7,500-£8,500 when Cat N
- Less impact than Cat S
Should You Buy a Cat N Car?
Yes - Cat N cars can be good value IF:
1. Price reflects category:
- 15-25% discount minimum
- More discount if damage was severe non-structural (e.g., flood/fire)
- £10,000 equivalent should be £7,500-£8,500
2. Damage type was minor:
- Good Cat N damage: Cosmetic panels, lights, minor theft damage, hail dents
- Concerning Cat N damage: Flood, fire, electrical systems, airbag deployment
3. Repairs appear professional:
- Clean bodywork
- Paint quality good
- Gaps between panels even
- No electrical issues
- Everything works as it should
4. You have repair documentation:
- Invoices for work done
- Parts receipts (genuine parts?)
- Photos before/after repair
- Professional shop used
5. No ongoing issues:
- Test drive reveals no problems
- No warning lights
- Electrics all work
- No strange smells (fire/flood damage)
- MOT history clean post-repair
6. Insurance available at reasonable cost:
- Many insurers cover Cat N with small or no premium increase
- Get quotes BEFORE buying
- Comprehensive cover available
When to AVOID Cat N Cars:
Walk away if:
- Flood damage (electrical gremlins forever)
- Fire damage to interior/wiring (ongoing issues likely)
- Airbag deployment without proof of genuine replacement (£800-£2,000 per airbag)
- No repair documentation
- Electrical issues present
- Seller didn't disclose Cat N status
- Price doesn't reflect appropriate discount
- Poor quality repairs visible
Cat N Sweet Spot:
Best Cat N buys:
- Cosmetic/panel damage only
- Hail damage (purely cosmetic dents)
- Minor theft damage (broken window, damaged ignition)
- Light collision damage (bumper, lights, bonnet)
- Professional repair with documentation
- Everything works perfectly
- Appropriate price discount
Insurance Implications of Write-Off Categories
How insurance companies treat write-offs:
Cat A and Cat B
Insurance:
- Should not exist as vehicles
- No legitimate insurer will cover
- If you see one insured, it's likely fraudulent
Cat S - Structural
Insurance implications:
Availability:
- Many mainstream insurers REFUSE to cover Cat S
- Specialist insurers available but limited
- Some mainstream insurers cover with restrictions
Premium impact:
- Typically 10-30% higher premium
- Some insurers: 50%+ increase
- Depends on insurer and damage severity
Coverage limitations:
- Some offer third-party only (no comprehensive)
- Higher excess common
- Agreed value policies may be refused
- Claims may be scrutinised more carefully
Insurer examples:
- Admiral, Direct Line, Aviva: Often refuse Cat S
- Specialist insurers: HIC, Keith Michaels, A-Plan - will cover
- Always get quotes BEFORE buying
Tip: Get insurance quotes with the specific VIN before purchasing. Don't assume you can insure it.
Cat N - Non-Structural
Insurance implications:
Availability:
- Most insurers will cover Cat N
- Much easier than Cat S
- Mainstream insurers generally accept
Premium impact:
- Often no increase or minimal (5-15%)
- Depends on damage type
- Flood/fire Cat N = higher premium
- Cosmetic Cat N = minimal impact
Coverage:
- Comprehensive cover usually available
- Standard terms in most cases
- Some insurers treat it like any other car
Much easier to insure than Cat S.
Declaring Write-Off Status
Legal requirement:
- MUST declare Cat S or Cat N when insuring
- Failure to declare = insurance invalid
- Claims can be rejected
- Prosecution possible for fraud
When selling:
- MUST declare write-off status
- Consumer Rights Act requires accurate description
- Non-disclosure is fraud
- Buyer can reject and get refund
Value Impact - How Much Less Are Write-Offs Worth?
Understanding depreciation helps you negotiate:
Category S (Structural)
Value reduction: 25-40%
Example:
- Clean car: £10,000
- Cat S equivalent: £6,000-£7,500
- Discount: £2,500-£4,000
Factors affecting value:
- Damage severity (minor vs major)
- Repair quality (excellent vs poor)
- Car type (prestige vs budget)
- Age (newer = bigger impact)
- Availability (rare cars less affected)
Depreciation continues:
- Cat S depreciates faster than clean cars
- Harder to sell
- Smaller buyer pool
- May need to accept lower offers
Category N (Non-Structural)
Value reduction: 15-25%
Example:
- Clean car: £10,000
- Cat N equivalent: £7,500-£8,500
- Discount: £1,500-£2,500
Damage type impact:
- Minor cosmetic: 15-20% discount
- Flood/fire/electrical: 20-30% discount
- Theft recovery (minimal damage): 10-15% discount
Less dramatic depreciation than Cat S but still significant.
Category C (Pre-2017)
Now called Cat S:
- Treated same as Cat S
- 25-40% value reduction
Category D (Pre-2017)
Now called Cat N:
- Treated same as Cat N
- 15-25% value reduction
Resale Considerations
When selling a write-off:
- Expect 20-40% less than clean equivalent
- Prepare for longer selling time
- Many buyers automatically reject write-offs
- Finance buyers often can't get loans
- Must declare status (illegal not to)
How to Check Write-Off Status
Before buying any used car, check if it's been written off:
1. HPI Check or Vehicle History Check (Essential)
The reliable method:
What it checks:
- Insurance write-off register (MIAFTR - Motor Insurance Anti-Fraud and Theft Register)
- All insurance companies report write-offs
- Categories A, B, S, N (and old C, D)
- Date of write-off
- Which insurer wrote it off
Providers:
- HPI Check: £19.99-£29.99
- CarSorted: £24.99 (includes service history check)
- AA Car Check: £19.99
- RAC Vehicle Check: £24.99
- MyCarCheck: £9.99-£24.99
All access same database (MIAFTR).
→ Get comprehensive write-off check from CarSorted
→ Learn more: Complete HPI Check Guide
2. Free Basic Checks (Limited)
Gov.uk vehicle enquiry:
- https://www.gov.uk/get-vehicle-information-from-dvla
- Shows: Make, model, colour, year
- Does NOT show write-off status
MOT history:
- https://www.gov.uk/check-mot-history
- Sometimes shows evidence (failed due to accident damage)
- Not reliable for write-off status
- But useful to see repair quality
Free checks DON'T show write-off categories reliably.
3. Ask the Seller Directly
Legal obligation:
- Sellers MUST disclose write-off status
- Non-disclosure is fraud (Consumer Rights Act)
- Ask directly: "Has this car ever been written off?"
Red flags:
- Seller hesitant or evasive
- Claims not to know (should check V5C)
- Becomes defensive
- Refuses to let you run checks
If seller didn't disclose and HPI reveals write-off:
- Dishonesty is major red flag
- What else are they hiding?
- Walk away immediately
4. Check V5C Registration Document
V5C may show:
- Nothing (write-off status not always shown)
- Note about vehicle category (if updated)
- Previous keeper was insurance company (giveaway)
Not reliable - always run HPI check.
Repair Quality Checks - Is It Safe?
If you're considering a Cat S or Cat N car, verify repair quality:
Professional Pre-Purchase Inspection
Worth every penny for write-offs:
What inspectors check:
- Chassis alignment (Cat S critical)
- Suspension geometry and tracking
- Structural integrity
- Evidence of previous damage
- Repair quality (professional vs DIY)
- Paint thickness (detecting filler)
- Panel gaps and alignment
- Weld quality
- Rust or corrosion from poor repair
- Safety systems functioning
- Electrical systems (Cat N flood/fire damage)
Cost: £150-£300
Where:
- AA or RAC inspection
- Independent vehicle inspectors
- Specialist bodyshop inspection
- Engineer's report for serious cases
For Cat S cars: Non-negotiable. Always get professional inspection.
DIY Visual Checks
What you can check:
Panel gaps:
- Should be even on both sides
- Uneven gaps suggest poor repair or bent frame
- Check doors, bonnet, boot
Paint quality:
- Look in daylight
- Mismatched colour = poor repair
- Orange peel texture = cheap paint job
- Overspray on trim/glass = careless work
Underneath inspection:
- Look for bent or damaged chassis
- Check for poor quality welds
- Fresh underseal may hide damage
- Rust or corrosion from water ingress
Alignment:
- Does car drive straight?
- Steering wheel centered?
- Tyres wearing evenly?
- No pulling to one side?
Warning lights:
- Any airbag warnings? (Replacement required)
- ABS/ESP lights? (Sensor damage)
- Any electrical issues?
Request Documentation
Ask for:
- Pre-repair damage photos (if available)
- Repair invoices (itemised)
- Parts receipts (genuine parts?)
- Insurance assessor report (sometimes available)
- Paint shop invoice
- Geometry alignment printout
- Engineer's report (if had one)
Red flags:
- No documentation available
- DIY repairs
- Unknown repair shop
- Cheap parts used
- Recent quick repair before sale
Cat S vs Cat N - Quick Comparison
| Feature | Cat S (Structural) | Cat N (Non-structural) |
|---|---|---|
| Damage Type | Structural/chassis/frame | Cosmetic/electrical/interior |
| Safety Concern | High (if poorly repaired) | Low to moderate |
| Value Reduction | 25-40% | 15-25% |
| Insurance | Difficult, expensive | Easier, reasonable |
| Resale | Very difficult | Moderately difficult |
| Inspection | Essential, non-negotiable | Recommended |
| Recommended? | Only with perfect repair proof | Can be good value |
| Risk Level | High | Low to moderate |
Common Myths About Write-Offs Debunked
Myth 1: "All Write-Offs Are Dangerous"
Truth:
- Cat S and N can be perfectly safe if repaired properly
- Many are written off for economic reasons, not safety
- Professional repair to manufacturer standards = safe car
- The issue is identifying WHICH ones were repaired properly
Myth 2: "Cat N Is Fine, No Problems"
Truth:
- Cat N can have serious issues if flood/fire damage
- Electrical problems from flood can persist for years
- Airbag replacement is expensive - verify it was done with genuine parts
- Still needs thorough inspection
Myth 3: "You Can't Finance a Write-Off"
Truth:
- Many finance companies DO finance Cat N cars
- Some finance Cat S (with restrictions)
- Depends on lender and damage severity
- Always check with lender before buying
Myth 4: "Write-Off Status Can Be Removed"
Truth:
- Category markers are PERMANENT
- Once Cat S, always Cat S
- No legal way to remove it
- Stays on databases forever
Myth 5: "All Insurers Refuse Write-Offs"
Truth:
- Cat N: Most insurers will cover
- Cat S: Specialist insurers available
- Premium increases vary (10-30% typically)
- Shop around for quotes
Myth 6: "Sellers Must Write 'Cat S' in the Advert"
Truth:
- No legal requirement to put in advert title
- But MUST disclose when asked or in description
- Non-disclosure is fraud (Consumer Rights Act)
- Buyer can reject and get refund if not disclosed
Write-Off Category Checklist
Use this checklist when considering a write-off:
Initial Discovery
- Run HPI or vehicle history check
- Confirm write-off category (A, B, S, N, C, D)
- Check seller disclosed it (if not, walk away)
- Verify damage type and severity
- Request repair documentation
For Cat A or B
- Walk away immediately
- Report to police and DVLA
- Do not proceed under any circumstances
For Cat S (Structural)
- Price reflects 30-40% discount minimum
- Obtain full repair documentation
- Review pre-repair photos
- Verify professional repair shop used
- Check genuine parts were used
- Book professional pre-purchase inspection
- Get insurance quotes BEFORE buying
- Verify damage was relatively minor
- Check MOT history post-repair
- Test drive - no pulling or alignment issues
- Accept resale will be difficult
For Cat N (Non-structural)
- Price reflects 15-25% discount minimum
- Identify damage type (cosmetic vs flood/fire)
- Request repair documentation
- Check all electrics work perfectly
- No warning lights on dashboard
- Test all features and systems
- No water damage smells
- Insurance quotes acceptable
- Consider professional inspection (recommended)
- Accept some resale difficulty
Before Purchase
- Professional inspection completed (Cat S: essential)
- Repair quality confirmed satisfactory
- Insurance quote obtained and acceptable
- Price negotiated reflects category discount
- Understand resale implications
- All documentation received and genuine
- Test drive satisfactory
- MOT history reviewed post-repair
What to Do If Undisclosed Write-Off Discovered
Found out after purchase? You have rights:
Within 30 Days (Dealer Purchase)
Consumer Rights Act 2015:
- Car must be as described
- Undisclosed write-off = misrepresentation
- Right to reject and full refund
Action plan:
- Gather evidence (HPI report showing write-off)
- Write to dealer immediately
- Cite Consumer Rights Act 2015
- Demand full refund
- Give reasonable time to respond (14 days)
- If refused, threaten legal action
- Contact credit card company (Section 75 claim)
- Report to Trading Standards
You have strong legal position.
After 30 Days (Dealer Purchase)
- Still have rights under Consumer Rights Act
- May get partial refund or price adjustment
- More complex but pursue anyway
- Trading Standards can help
- Citizens Advice for guidance
Private Purchase
Misrepresentation Act 1967:
- Seller must have described car accurately
- Non-disclosure of write-off status is misrepresentation
- You can seek refund or compensation
Action plan:
- Contact seller with evidence
- Request refund or compensation
- If refused, consider small claims court
- Report to Action Fraud
- Seek legal advice
Harder than dealer purchase but still possible.
Credit Card Protection
Section 75 claim:
- If paid by credit card (£100-£30,000)
- Card company jointly liable
- Claim refund from card company
- Often easier than pursuing seller
Conclusion
Write-off categories determine whether a previously damaged car is safe, legal, and good value. Understanding them is essential for any used car buyer.
Key takeaways:
Never buy:
- Cat A or Cat B (illegal, should be scrapped)
Consider carefully:
- Cat S (structural damage) - Only with perfect repair proof, 30-40% discount, and professional inspection
- Cat N (non-structural) - Can be good value with 15-25% discount if damage was minor and cosmetic
Always check:
- Run HPI check (£20-30) before buying ANY used car
- 400,000+ write-offs on UK roads
- Sellers don't always disclose
- 60-second check could save £2,000-£4,000
If buying a write-off:
- Appropriate price discount (25-40% Cat S, 15-25% Cat N)
- Full repair documentation
- Professional pre-purchase inspection (Cat S: essential)
- Insurance quotes obtained first
- Accept resale difficulties
- Walk away if anything feels wrong
Don't take chances: For the cost of an HPI check (£20-30) and professional inspection (£150-£300), you can verify whether a written-off car has been repaired safely or is a dangerous bargain that will cost you thousands.
Ready to check a car's write-off status? Get comprehensive vehicle history check from CarSorted →