Conditions for Winning a Depreciation Case and Things to Consider

1) Core requirements to “win” a diminished value claim

In practice, four main pillars are critical for a diminished value claim to be accepted:

1. Proving the accident and fault

• Evidence that the traffic accident occurred (accident report, police/gendarmerie record, CCTV footage, witnesses).

• Proof that the other party was at fault (the higher the fault percentage, the stronger the likelihood of acceptance and a higher award).

2. Damage that actually causes a loss in market value

• The vehicle must have sustained damage, and that damage must be capable of reducing market value.

• Replaced/painted/repaired parts—especially repairs to structural areas (chassis, pillars, etc.)—generally make diminished value more “provable.”

3. Directing the claim to the correct party

• In most cases, the claim is pursued under the at-fault vehicle’s Compulsory Traffic Liability Insurance within policy limits.

• If the policy limit is exceeded, the remaining amount may be pursued against the at-fault driver/operator and, depending on the circumstances, other coverages (e.g., voluntary third-party liability / increased limits).

• There are Court of Cassation (Yargıtay) decisions recognizing diminished value as a “real/actual loss” item and holding the traffic insurer liable within policy limits.

4. Compliance with deadlines and procedural requirements

• A written application to the insurer is often the “door-opening” step in many files: under KTK Art. 97, an application must be made to the insurance company before filing a lawsuit/arbitration, and if no response is given within 15 days or the claim is not paid, the claimant may proceed with litigation/arbitration.

• Regarding limitation periods (for property damage claims), KTK Art. 109 provides a two-year period and, in any event, a ten-year long-stop approach (implementation may vary depending on the nature of the case).

2) What to do before filing (steps that increase your chances)

A) Collect a complete evidence package

• Accident report / police report

• Damage photos (before/after, if possible)

• Service invoices, parts list, labor breakdown

• Expert appraisal report / service report

• TRAMER/claim record, mileage information

• Listing comparisons (price analysis of damaged vs. undamaged vehicles within the same make/model/year/trim/mileage band)

B) Ground the market value and diminished value method in “real market conditions”

The most disputed points in expert/witness reports are usually:

• How was the “pre-accident market value” determined?

• Which comparables were used to prove the accident’s impact on market price?

Tip: Using 8–12 comparable listings with the same trim/body/version and a close mileage range strengthens the report.

C) Submit a proper application to the insurance company

If you intend to apply to Insurance Arbitration, you generally need to apply to the insurer first.

3) Lawsuit or Insurance Arbitration?

Option 1: Insurance Arbitration Commission

• If the insurer is a member of the arbitration system and conditions are met, this can be a faster route.

• Application procedures and required documents are detailed on the Commission’s pages.

Option 2: Court lawsuit

• If the insurer does not pay or underpays, the claim is taken to court.

• The aim is to have fault + damage + market value + diminished value amount confirmed through expert examination.

4) Is mediation mandatory?

This issue can be debated in practice and may be case-specific:

• In compulsory traffic insurance disputes, the “application to the insurer” (KTK Art. 97) is often treated as a precondition, and some views/decisions consider that additional mandatory mediation may not be required.

• On the other hand, the “commercial case” characterization and the scope of TTK Art. 5/A (mandatory mediation as a precondition for monetary claims) set the general framework.

Practical suggestion: Strategy should be determined by assessing the parties, the target of the claim (insurer vs. operator), the commercial nature of the dispute, and local practice.

5) Most common mistakes that lead to losing

• Filing for a high amount without clarifying the fault ratio

• Choosing incorrect market comparables (trim/body differences)

• Failing to document the application/response timeline and correspondence (KTK Art. 97)

• Not directing the portion exceeding the policy limit to the correct parties

• Weak technical objections to expert reports (comparables, parts/labor details, damage location)

6) “Win checklist”

• ✓ Fault ratio and accident evidence are complete

• ✓ Damage location/repair type is clear (replacement/paint/structural)

• ✓ 8–12 comparable listing analysis is ready

• ✓ Written insurer application + timeline tracking is in place (KTK 97)

• ✓ Strategy chosen: arbitration or lawsuit (evidence set ready)

• ✓ Policy limits and the “excess over limit” plan are mapped out