Vehicle Diminished Value Calculation

Diminished value is the difference between your vehicle's second-hand value before the accident and after repair. Calculate it, and if an amount has already been notified to you, compare the two. The period for objecting to the report is only three business days.

The results are based on the second-hand values you declare and are not an expert or court-expert calculation. If you do not know the market values, the tool produces no figure; instead it shows the criteria by which compensation is determined.

The calculator itself is available on the Turkish page: link. Linked pages are in Turkish.

The vehicle's second-hand values

Diminished value is the difference between the vehicle's second-hand market value before the accident and after repair. If you do not know these two values, you can leave them blank. In that case no amount is calculated, and we show what the compensation is based on.

Comprehensive motor insurance (kasko) value lists and the classified-ad market are the starting point for the pre-accident, undamaged value. The post-repair value is what the same vehicle would fetch with its damage record and repair history. The calculator also asks for the accident date and the other party's share of fault as recorded in the accident report; the part corresponding to your own fault cannot be claimed from the insurer. Finally, it asks whether the vehicle was withdrawn from traffic or scrapped because of the damage.

Have you been notified of an amount?

If the expert report or the insurer's notification states a diminished-value amount, enter it and compare it with the calculation. The period for objecting to the report is three business days. If you also enter the notification date, the tool shows the last day.

Condition of the vehicle (optional)

This information does not directly calculate the amount. These are the criteria taken into account when compensation is determined, and they are passed on to the attorney before the consultation: vehicle age, mileage, policy date, which areas were damaged, whether parts were replaced, whether there was a damage record before the accident, commercial or rental use, and whether the claim rests on an optional third-party liability (İMSS) policy.

What Is Vehicle Diminished Value?

A vehicle damaged in a traffic accident is treated as an "accident vehicle" in the second-hand market even if it has been repaired to the highest standard, and it finds a buyer only at a lower price. This drop in value is a real loss: it must be compensated under the tort provisions of the Turkish Code of Obligations (TBK), and it is claimed from the other party's compulsory motor third-party liability insurance.

The fact that the replaced parts are original does not on its own eliminate diminished value. That the vehicle has had parts replaced and has undergone repair affects its second-hand value.

How Is Diminished Value Calculated?

Settled practice uses a single criterion: the difference between the vehicle's undamaged second-hand market value on the date of the accident and its second-hand market value after repair. The part corresponding to the claimant's own fault is deducted from the resulting amount.

Summary of the method

Diminished value = undamaged second-hand value − post-repair second-hand value

Amount payable = diminished value × the other party's share of fault

1 July 2026: two methods brought into line

The diminished-value clause of the general conditions for compulsory motor third-party liability insurance was redrafted in the Official Gazette of 12 June 2026 and entered into force on 1 July 2026. The new text provides that diminished value is to be determined by taking into account the vehicle's make, age, model, degree of use, the areas damaged and its prior damage history, together with the difference between its pre-accident and post-repair second-hand sale values. The reference to the coefficient table in the old text was removed. Because amendments to the general conditions apply to policies issued after the effective date, the date of your policy determines which text applies.

These two values are determined by examining comprehensive insurance value lists and the classified-ad market and by inspecting the vehicle's physical condition. Diminished value therefore cannot be found with a fixed percentage or a table, and the tool likewise produces no figure unless you enter the values.

The 2026 Process: Expert Assignment and a Single Report

The Regulation on the Assignment of Insurance Experts (Official Gazette of 12 February 2026, in force from 1 April 2026) introduced the sequential assignment of insurance experts (eksper) through a central system in motor third-party liability insurance. When assessing the damage, the assigned expert must also calculate diminished value in the same report, observing the principle of actual loss.

The practical consequence is this: in a file to which an expert has been assigned, you do not need to file a separate application for diminished value. In a file with no expert assigned, an expert is assigned once you claim diminished value.

Coverage is expanding in stages

Sequential expert assignment was first piloted in Bursa and Ordu. By a Board decision dated 30 June 2026, the period was extended to 1 August 2026, and Balıkesir, Erzurum, Kayseri, Kütahya, Manisa, Uşak and Van were added to the scope. There is no regulation announcing that the practice has been rolled out nationwide. You therefore need to check which procedure applies in your file and whether an expert has been assigned.

Objecting to the Report: Three Business Days

The expert's findings can be objected to within three business days of the notification that the report has been entered into the system. This period is very short, and it is the fastest route available to you against the diminished-value amount.

1. Objection. An objection is filed within three business days of the notification; a second expert is then assigned through the system.
2. Second expert report. If requested within three business days of the notification of the second report, an umpire expert is assigned.
3. Umpire expert. Appointed from among persons who have actively worked as experts in the relevant branch for at least ten years; the report they draw up is treated as final.

Having exhausted this route at the expertise stage does not by itself close the way to the Insurance Arbitration Commission and the courts. Missing the deadline, however, may leave you with a longer and more costly path.

When Diminished Value Cannot Be Claimed

• Scrapped or withdrawn from traffic: diminished-value claims for vehicles that have been withdrawn from traffic or scrapped because of the damage fall outside compulsory motor third-party liability insurance.
• Your own share of fault: the part corresponding to the claimant's own fault is outside coverage; compensation is paid only in proportion to the other party's fault.
• Consequential losses: loss of use, replacement vehicle costs, loss of earnings and business interruption cannot be claimed from compulsory insurance; these are assessed separately against the party at fault.
• Non-pecuniary damages: outside the scope of compulsory motor third-party liability insurance.
• Optional third-party liability policy (İMSS): it comes into play only after the compulsory insurance limits are exhausted, and if the policy has no diminished-value cover, this item is not paid.

Insurance Arbitration and Court Proceedings

Before going to court or arbitration, a written application to the insurer is a precondition for filing suit. If no reply is given within fifteen days, or the reply does not satisfy the claim, you may apply to the Insurance Arbitration Commission or file a lawsuit.

An application made while the expertise is ongoing may be turned away

Under the Agency Circular dated 5 August 2026, if the insurer documents that it assigned an expert within the time limit and that the report could not be completed for reasons not attributable to it, the claim is not deemed to have been rejected, nor the reply deemed not to satisfy the claim. At this stage the right step is not to rush to arbitration but to object to the report in time.

In arbitration, from 22 January 2026 onward, arbitrator decisions in disputes below TRY 35,000 are final; at or above that amount, an objection may be filed with the Commission. In court proceedings, the competent court depends on whom you sue: the Commercial Court of First Instance for claims against the insurance company, and the Civil Court of First Instance for claims against the driver or operator at fault.

The limitation period is two years from the date the loss and the party liable for compensation become known, and in any event ten years from the day of the accident. If the accident also constitutes a criminal offense, the longer period under the criminal law applies.

Frequently Asked Questions

What is vehicle diminished value?

A vehicle damaged in a traffic accident finds a buyer only at a lower price in the second-hand market because of its accident record, even if it has been repaired to the highest standard. This drop in value is a real loss and is claimed from the other party's compulsory motor third-party liability insurance.

How is diminished value calculated?

The basis is the difference between the vehicle's undamaged second-hand market value on the date of the accident and its second-hand market value after repair. The part corresponding to the claimant's own fault is deducted from the resulting amount. Because these two values are determined through market research and a physical inspection of the vehicle, the amount cannot be found with a table or a fixed percentage.

What changed as of 1 July 2026?

The diminished-value clause of the general conditions for compulsory motor third-party liability insurance was redrafted in the Official Gazette of 12 June 2026 and entered into force on 1 July 2026. The new text provides that diminished value is to be determined by taking into account the vehicle's make, age, model, degree of use, the areas damaged and its prior damage history, together with the difference between its pre-accident and post-repair second-hand sale values. The reference to the coefficient table in the old text was removed.

Do I need to file a separate application for diminished value?

If an expert has been assigned to your file, diminished value is calculated in the same report, and no separate application is needed. If you claim diminished value in a file with no expert assigned, an expert is assigned on that basis. Because the provinces and procedures covered are expanding in stages, the situation in your own file needs to be checked.

Can I object to the diminished-value amount in the expert report?

Yes. The expert's findings can be objected to within three business days of the notification that the report has been entered into the system. On objection, a second expert is assigned. If requested within three business days of the notification of the second report, an umpire expert with at least ten years of experience in the relevant branch is assigned, and the umpire expert's report is treated as final.

What happens if I miss the objection period?

The start of the period depends on when the notification reached you, and this may be disputed in a given case. Even if the objection route at the expertise stage is closed, the Insurance Arbitration Commission and the courts are assessed separately. It is therefore worth having the file reviewed even if the period appears to have passed.

What can I do if the insurance company pays a low amount?

A written application must first be made to the insurer; this application is a precondition for filing suit. If no reply is given within fifteen days, or the reply does not satisfy the claim, you may apply to the Insurance Arbitration Commission or file a lawsuit.

Can I apply to arbitration before the expert report is completed?

Under the Agency Circular dated 5 August 2026, if the insurer documents that it assigned an expert within the time limit and that the report could not be completed for reasons not attributable to it, the claim is not deemed to have been rejected. An arbitration application made at this stage may be turned away at the preliminary review. The right step is not to hurry the application but to object to the report in time.

Can I claim diminished value if my vehicle was scrapped?

Under the Highway Traffic Law (KTK), diminished-value claims for vehicles that have been withdrawn from traffic or scrapped because of the damage fall outside compulsory motor third-party liability insurance. Whether the loss can be claimed from the party at fault under the general provisions must be assessed separately.

Is compensation reduced if I was partly at fault?

Yes. The part corresponding to the claimant's own fault is outside the scope of compulsory motor third-party liability insurance; compensation is calculated only on the other party's share of fault. In an accident caused entirely by your own fault, diminished value cannot be claimed.

Can I claim the cost of a replacement vehicle for the repair period?

Consequential losses such as loss of use, loss of earnings and business interruption are outside the scope of compulsory motor third-party liability insurance. These claims are assessed separately against the party at fault under the general provisions.

Which court hears a diminished-value case?

The competent court depends on whom the case is brought against. Cases against the insurance company are treated as commercial cases by their nature, so the Commercial Court of First Instance is competent. In a tort-based case against the driver at fault, the operator or the vehicle owner, the Civil Court of First Instance is competent.

What is the limitation period for a diminished-value claim?

Two years from the date the loss and the party liable for compensation become known, and in any event ten years from the day of the accident. If the accident also constitutes a criminal offense, the longer limitation period provided in the criminal law applies, so the calculation depends on the specific file.

Review your expert report with Att. Mesut İlme

Whether the notified amount is appropriate, the objection period and the route to follow are determined according to your file. Book an online or in-person appointment.

Book an Online Appointment · 0 (226) 911 07 99

Consultation fees start at TRY 4,800 (VAT included).

Related Tools and Guides

• Traffic Accident Compensation Calculator: bodily injury compensation in accidents involving injury or death.
• Traffic Accident Compensation Lawsuit: the litigation process, evidence and the procedure for applying to the insurer.
• Traffic Accident Lawyer in Yalova: case handling and the local process in Yalova and the surrounding area.