Diminished value after a car accident in Türkiye: what it is and how to claim it (new rules from 1 July 2026)

However well your car is repaired after an accident, on the second-hand market a vehicle with a damage record will not sell for the same price. The difference between its value before the accident and its value after repair is called diminished value (değer kaybı). If you were not at fault, or only partly at fault, this loss can be claimed from the compulsory motor insurer of the vehicle that caused the accident. The calculation method changed on 1 July 2026; this article explains the new rules and how to pursue a claim.

Why does a car lose value?

Anyone buying a used car checks its damage history. Records of vehicles damaged in traffic accidents and handled by insurers are kept by the Insurance Information and Monitoring Centre, and buyers can easily look them up. The more parts that were replaced or repainted, the lower the market value. This drop happens regardless of the quality of the repair and is part of the loss caused by the accident.

What changed on 1 July 2026?

Amendments to the General Conditions of Compulsory Motor Third Party Liability Insurance, published in the Official Gazette on 12 June 2026, took effect on 1 July 2026. The main changes for diminished value are:

Since the Constitutional Court's 2020 decision, courts had already been assessing diminished value through expert reports based on real market conditions. The new rules bring the insurer-stage calculation closer to that "actual loss" approach.

Who is the claim made against?

The claim is made against the compulsory motor third party liability (traffic) insurer of the vehicle at fault. The insurer's liability is limited to the policy limits; the driver and the keeper of the vehicle are also liable for any loss above those limits.

Whether you can recover diminished value under your own comprehensive (kasko) policy depends on the policy terms and is disputed in practice. The main target of a diminished value claim is therefore the other party's traffic insurer.

Step by step

1. A written application to the insurer is mandatory

Under Article 97 of the Highway Traffic Law, the injured party must apply in writing to the insurer before filing a lawsuit or applying for arbitration. If the insurer does not respond within fifteen days of the application, or its response gives rise to a dispute, a lawsuit or arbitration may follow. A lawsuit filed without this application is dismissed on procedural grounds.

2. The expert assessment and the insurer's offer

Under the new General Conditions, diminished value is set according to the difference in second-hand values determined by the appointed insurance expert. Always review the report and the amount offered: if the mileage, equipment, earlier damage or the nature of the repair is not reflected correctly, the amount may fall short of the real loss.

3. Insurance Arbitration Commission or court

If there is a dispute, there are two routes. The Insurance Arbitration Commission is available where the insurer is a member of the system and usually reaches a decision faster than the courts; awards below a certain amount are final. In court, diminished value is determined by an independent expert report. Which route to choose depends on the amount, the evidence and how quickly you need a result.

What affects the amount?

Your share of fault matters. If you were partly at fault, diminished value is paid in proportion to the other party's fault. For example, if you were found 25 per cent at fault, you can claim 75 per cent of the assessed loss. Fault is established from the accident report, camera footage and, where necessary, an expert examination.

When can it not be claimed?

• When you were entirely at fault,
• When the car is declared a total loss; compensation is then based on the car's market value at the date of the accident rather than on diminished value,
• When the same part already had a damage record, the claim may be limited or rejected,
• When the limitation period has expired.

Limitation period

Under Article 109 of the Highway Traffic Law, a claim becomes time-barred two years after the injured party learns of the loss and of the party liable, and in any event ten years after the accident. If the accident also constitutes a criminal offence with a longer limitation period, that longer period applies.

Legislation and sources

• Highway Traffic Law No. 2918: Arts. 85, 91 and 97
• Insurance Law No. 5684: Art. 30 (Insurance Arbitration Commission)
• General Conditions of Compulsory Motor Third-Party Liability Insurance (amended in the Official Gazette of 12.06.2026, in force 01.07.2026)
• Code of Obligations No. 6098: Arts. 49 and 51-55 (tort and damages)

The current texts of Turkish laws and regulations are available on the official Legislation Information System, and decisions and amendments in the Official Gazette.

For diminished value, vehicle damage and other compensation claims after an accident, please contact us.