If your car has been in an accident, the first question is: what was it worth before the crash? That figure determines whether your insurer repairs or writes it off. Enter your reg above to get a free market estimate based on what identical cars are actually selling for at UK dealers right now.
How insurers decide to write off your car
Your insurer compares the cost of repairing your vehicle against its pre-accident market value. If the repair bill crosses a certain percentage of that value, the car is declared a total loss. Most UK insurers set this threshold between 60% and 70%. Some go as low as 50%, especially for older cars where sourcing parts becomes difficult or where corrosion is likely to cause complications during the repair.
That threshold is applied to the total cost of dealing with the claim, not just the visible repair work. Recovery fees, vehicle storage, engineer inspections, courtesy car provision, and VAT all count. A repair quote of £5,000 on an £8,000 car looks manageable at 63%. But add £400 in storage, £150 for recovery, and £200 for the engineer's report, and the real figure is £5,750 - suddenly 72% and over the line.
This is why knowing your car's pre-accident value matters. If you can demonstrate the market value was higher than the insurer assessed, you shift the maths. A £1,500 difference in valuation can be enough to push a borderline case from write-off back to repair.
The four UK write-off categories
The UK classifies written-off vehicles into four categories. Understanding which one applies to your car affects whether it can ever return to the road, what it's worth as salvage, and what appears on future vehicle history checks.
The entire vehicle must be crushed. Nothing can be salvaged. Typically reserved for fire damage or catastrophic structural failure.
The body must be crushed, but usable parts like the engine, gearbox, and electronics can be stripped and sold. The car never drives again.
The chassis, subframe, or structural panels were damaged. Repairable and can legally return to the road, but the write-off marker stays on the vehicle's record permanently.
No structural damage, but repair costs exceeded the insurer's threshold. Common causes include deployed airbags, flood damage to electrics, or cosmetic damage on lower-value cars. Can return to the road.
If you're buying a used car, always check whether it carries a write-off marker. Our free car check shows write-off history as part of the standard report.
Why the same damage gets different outcomes at different insurers
Two identical cars with the same damage can get different decisions from different insurers. This isn't random. Insurers that have strong relationships with salvage buyers can afford to write off more cars because they recover more money through salvage sales. An insurer that expects to recoup 40% at salvage auction is more comfortable declaring a total loss than one that only recovers 20%.
Labour rates also play a role. Insurers with networks of approved repairers paying £45 per hour see lower repair bills than those using garages charging £75. The same physical damage produces a different number on the estimate, which changes whether the threshold is crossed.
The type and age of the car shifts things too. A nearly-new premium car with expensive parts and steep depreciation might get written off at 60% damage. An older commercial van that the owner needs operational might survive 80% because the salvage value is minimal and the business cost of being without it outweighs the repair bill.
The hidden costs that push repairs over the threshold
The repair estimate your insurer works from includes far more than the visible bodywork. Every element of dealing with the claim gets factored in:
- Parts replacement (new or approved aftermarket)
- Labour at approved repairer rates
- Paint, materials, and specialist subcontracted work
- Vehicle recovery and storage (which accumulates daily)
- Independent engineer's inspection report
- Courtesy car provision during the repair period
- VAT on the entire repair bill
Modern vehicles add another layer. If a car has radar sensors, parking cameras, or lane-keeping systems in the damaged area, those components need replacing and recalibrating. Sensor replacement can run £500 to £1,500, with calibration adding another £200 to £400. On a car worth £12,000, that alone can tip the balance.
Older cars face the opposite problem. Corroded bolts snap during disassembly. Replacement panels don't sit right on worn mountings. What started as a straightforward wing replacement turns into an open-ended job, and insurers know this from experience. That's why thresholds drop for older vehicles.
The engineer's inspection
Before committing to a significant repair, insurers send an independent engineer to assess the damage. Their report carries substantial weight. They're not just listing what's visibly broken - they're looking for signs of hidden damage that might only emerge once panels are removed: chassis misalignment, subframe distortion, wiring loom damage behind trim panels.
If the engineer flags a risk that repairs may not restore the car to its pre-accident condition, the insurer will lean towards writing it off. They're protecting themselves from future claims about ongoing problems or diminished value. An initial repair quote of £3,000 can grow significantly once an engineer identifies potential structural complications that weren't visible from the surface.
What to do if you disagree with the decision
You're not obliged to accept your insurer's write-off decision without question. If you think they've undervalued your car, get an independent market estimate. Enter your reg above to see what comparable cars are actually selling for. If there's a meaningful gap between our figure and your insurer's, that's evidence you can use to challenge their assessment.
You can also get repair quotes from independent garages. Insurer-approved repairers don't always offer the most competitive rates, and a lower repair figure changes the threshold calculation. The insurer isn't required to accept your quote, but a significant difference strengthens your position.
If the insurer won't budge and you want to keep the car, ask about buy-back. You receive a settlement minus the salvage value and keep the vehicle to repair yourself. This makes particular sense for Category N write-offs where the damage is non-structural but exceeded the cost threshold.
Common write-off questions
What percentage of damage makes a car a write-off?
Most UK insurers use a threshold between 60% and 70% of the car's pre-accident market value. Some apply 50% for older vehicles. It's not just the repair bill - storage, recovery, engineer fees, courtesy car, and VAT all count towards the total.
Can a Category S or N car go back on the road?
Yes. Both Category S (structural) and Category N (non-structural) vehicles can legally be repaired and driven again. The write-off marker stays on the vehicle's record permanently, which typically reduces its resale value by 20-30% compared to an equivalent car with a clean history.
How do I check if a car has been written off?
Use our free car check to see whether any vehicle has a write-off marker. Our premium report includes full history from the insurance industry database, covering all four categories.
Should I accept my insurer's first offer?
Not necessarily. Insurer valuations are often conservative. Get an independent market estimate to check whether their figure reflects what your car was genuinely worth. If comparable cars are selling for more at dealerships, you have grounds to negotiate a higher settlement.
Is this tool free?
Yes. Enter your reg above for a free market estimate. No sign-up needed. We track asking prices across thousands of UK dealerships daily, so the figure reflects what the market looks like right now.