Turkish Late-Payment Surcharge Calculator
Enter the unpaid tax, fee or social security premium, its due date and the payment date. The late-payment surcharge, and for premiums the late penalty, is worked out period by period with the rate history.
- Unpaid amount50,000.00 ₺
- Current monthly rate3.7%
- As a share of the debt43.86%
- Surcharge21,928.33 ₺
- Total to pay71,928.33 ₺
Late-payment surcharge rate: Cumhurbaşkanlığı (CB kararı) / GİB
SGK late-payment penalty and surcharge: SGK being checked against the source
Breakdown by rate period
How it is calculated
The surcharge on late public debts such as taxes, fees and administrative fines runs from the day after the due date to the payment date and is not compounded. Social security premiums follow Art. 89 of Law 5510 instead: a late penalty for the first three months, then a compounded surcharge at a monthly rate SGK publishes from the Treasury’s average discount-bill yield. When a rate changes, each period uses its own rate.
Amme alacağı: Zam = Borç × Aylık oran × (Ay + Gün ÷ 30); SGK: Borç_k = (Borç_k−1 + Ceza_k) × (1 + Oran_k)Tax and other public debts use the monthly rate of Art. 51 of Law 6183 (3.7% since 13 Nov 2025); the surcharge is simple, charged month by month, with part months by the day. Social security premiums get a late penalty of 3% of the premium for each of the first 3 months; the balance then grows at SGK’s monthly rate, compounded, by the day in the month of payment.Example
A ₺50,000 tax debt due on 26.01.2026 and paid on 05.05.2026 is 3 months 9 days late: 50,000 × 3.7% × 3.3 = ₺6,105. A ₺100,000 March 2026 premium due on 30.04.2026 and paid on 15.06.2026 gets a ₺3,000 penalty and ₺3,090 surcharge (3.00%) for May, then ₺3,000 and ₺1,630.90 (2.99%) for 15 days of June: ₺10,720.90 in all.
Frequently asked questions
What is the surcharge rate?
For public debts, 3.7% a month since 13 Nov 2025. For social security premiums the rate changes monthly; the latest published rate is 2.91% a month.
How large is the SGK late penalty?
3% of the unpaid premium for each of the first 3 months. Even one day late triggers the first month’s penalty in full.
When does the surcharge stop?
It runs until the debt is paid. If the debt is rescheduled (tecil), deferral interest replaces it from that date.