Update your work experience certificate

Which month's index is used

(b) Jobs tendered under 4734

Denominator: the index of the month before the month of the tender date of the certificate's job. The tender date counts, not the contract date; taking the contract date is a common mistake.

(a) Unit prices published once a year

For jobs contracted with a tender discount on the estimate's unit prices, the denominator is the index of December of the year before the year the contract's unit prices belong to (art. 49/1-a-2).

(a) Unit prices published more than once a year

Denominator: the index of the month before the month the contract's unit prices were taken from (art. 49/1-a-1). The rule took effect on 13.05.2026; the tool applies it only to tenders announced on or after that date.

(c) Other jobs

For jobs outside (a) and (b), private sector jobs for example, the denominator is the index of the month before the month the certificate's job was contracted.

(d) Subcontractors' completion certificates

The regulation says these are updated "on the basis of the date of the contract signed between the contractor and the subcontractor", without naming the month. As in (c), the tool uses the month before that date's month. Art. 49/2 also ties foreign currency subcontractor certificates to (c).

Numerator: the month before the first announcement

The numerator is the same under every point: the index of the month before the month of the first announcement or invitation of the tender you are entering. The first announcement counts, not the tender (bid) date.

Foreign currency contracts

The amount is turned into lira at the CBRT buying rate published in the Official Gazette: on the tender date for a job tendered under 4734, on the contract date for other certificates, subcontractors' included. A 4734 job is then updated under (b), the others under (c) (art. 49/2).

Index: Domestic PPI (general)

Under the regulation the index is the general Domestic Producer Price Index published by TÜİK (art. 4/1-h). The tool uses the site's general Domestic PPI series (2003=100).

Which tenders

Art. 49 was rewritten as a whole on 13.08.2018; the tool covers tenders announced on or after that date. Point (a) changed on 13.05.2026 with no transitional clause, so tenders announced before that date keep the December rule.

• Price IndicesDomestic PPI sub-indices and CPI, monthly tables since 2012.
• Price Adjustment CalculatorPrice adjustment with the official formula, from Domestic PPI and CPI.
• Progress Payment Deductions CalculatorThe cover's VAT, every deduction from a) to k) and the net amount paid to the contractor, on one sheet.
• Quantity Takeoff CalculatorRebar, concrete, formwork and excavation takeoffs: a measurement sheet with deductions, exact totals and a copy for Excel.
• Index Change CalculatorHow Domestic PPI and CPI moved since your tender month, with the In/Io ratio.
• Stamp Duty CalculatorThe 9.48 per mille stamp duty on a progress payment, with the yearly cap.
• VAT Withholding CalculatorThe VAT withheld on a progress payment, at the communiqué's rate for the work type.
• Withholding Tax CalculatorWithholding tax on a multi-year construction payment, at the rate for the work type and payment month.
• Performance Bond CalculatorThe performance bond on a bid, with the below-limit 9% rule and additional bonds.
• Minimum Labour CalculatorThe minimum labour to declare for the SGK clearance, the shortfall and its estimated premium.
• Advance Payment CalculatorThe advance, its 30% or one-third cap, the recovery rate and what comes off each progress payment.
• Work Increase CalculatorThe work increase room left under the 20% (unit price) or 10% (lump sum) limit.
• Completion Compensation Calculator5% of the shortfall when work ends below 80%, updated to the acceptance month by Domestic PPI.
• Delay Penalty CalculatorThe delay penalty from the first contract price, daily rate and days late, with the 15% cap.
• Work Duration CalculatorCompletion date from the site handover, days late, final acceptance and payment deadlines.
• Fuel PricesEPDK monthly averages by fuel type, for the fuel coefficient of a price adjustment.