Statutory interest calculator Bulgaria 2026: late payment
Calculate statutory default interest on an overdue debt in Bulgaria. See the 2026 rate (10.15%), when you can claim it and how to work it out step by step.
Does someone owe you money and is slow to pay? Or are you the one with an overdue debt, wondering what interest is building up? Statutory default interest is easy to work out if you know the right rate for 2026.
Below you can calculate the interest in seconds and find out when you are entitled to claim it.
❓What is the statutory interest rate and how is it calculated for 2026?
Source: Council of Ministers Decree (ПМС) No. 347/2025 (amending No. 426/2014)
Statutory interest calculator
Enter the principal (the amount of the debt), the day the delay starts and the day of payment. The calculator uses the annual rate for 2026 and divides it by 360 days.
Calculator: statutory default interest
Annual rate (ECB main refinancing rate 2.15% + 8 p.p.)
10.15%
Days of delay
151 days
Daily interest
1.41 euro
Total default interest
212.87 euro
Total due (principal + interest)
5,212.87 euro
The calculator uses the annual rate for the first half of 2026 (10.15%) and the formula days x principal x rate / 360. It is accurate for periods entirely within 1 January to 30 June 2026. For older periods, or a delay that spans the change of half-year, the rate changes, so use the official interest calculator of the National Revenue Agency (НАП).
Take care with older periods
Ask Pravko and get an answer with citations from the law.
When you are entitled to statutory interest
Anyone who does not pay a money debt on time owes statutory default interest. These are the most common situations in which you can claim it:
Cases in which statutory interest is due
Interest runs from the day of the delay
An unpaid invoice or an unperformed money obligation under a contract
A late rent instalment from a tenant
A sum awarded by a court judgment that the debtor is slow to pay
A loan to a friend or relative that has fallen due
Overdue obligations to НАП, the National Social Security Institute (НОИ) and the health insurance fund
Here the state charges the interest itself
What matters is the day from which interest runs. If the contract sets a deadline (due date), the delay begins immediately after it. If no deadline is set, interest runs from the day you send a written demand for voluntary payment.
Obligations and Contracts Act (ЗЗД)
Art. 86(1)
Official Bulgarian text
„При неизпълнение на парично задължение длъжникът дължи обезщетение в размер на законната лихва от деня на забавата.“
Statutory, contractual and moratory interest: what is the difference
These three terms are often confused. Here is a short explanation of what each means and when it applies.
| Type of interest | What it is | When it applies | Amount |
|---|---|---|---|
| Statutory | Set by law when nothing else is agreed | Delay where no interest was agreed | From 01.01.2026: ECB main refinancing rate + 8 p.p. (before 2026: ОЛП + 10 p.p.) |
| Contractual | Agreed between the parties in a contract | When you have written it into the contract | As much as you agreed, within the bounds of good morals |
| Moratory | Compensation for delay (late-payment interest) | When a payment is overdue | May be statutory or agreed |
Moratory interest under Art. 86 ЗЗД is most often precisely the statutory interest.
How it is calculated: an example
Suppose a client owes you €5,000 on an invoice and delays payment by 120 days in 2026. This is how the interest builds up at an annual rate of 10.15%:
Example: €5,000, 120 days of delay
Principal (amount due)
€5,000.00
Annual rate (2.15% + 8 p.p.)
10.15%
Daily interest (5,000 x 10.15% / 360)
€1.41
Interest for 120 days
€169.17
Total due (principal + interest)
€5,169.17
The calculation is indicative and applies to periods entirely within the first half of 2026.
How to claim statutory interest
The interest does not need to be written down anywhere for you to claim it. It is owed by law. Here are the steps:
Steps to claim statutory interest
Establish the due date or send a demand
If a deadline was agreed, the delay runs after it. If not, send a written demand for voluntary payment.
Calculate the interest for the period of delay
Use the calculator above for periods in 2026, or the official НАП calculator for older periods.
Demand the principal plus interest in writing
Send a demand with the exact sums and a deadline for payment.
If they refuse: go to court
File an application for an order for payment (заповед за изпълнение) under Art. 410 of the Civil Procedure Code (ГПК), or bring a claim.
Common mistakes and important points
Outdated calculators give the wrong result
There are a few more things that are often overlooked and can cost you money:
The limitation period for interest is only 3 years
Obligations and Contracts Act (ЗЗД)
Art. 111, letter “в”
Official Bulgarian text
„С изтичане на тригодишна давност се погасяват вземанията за наем, за лихви и за други периодични плащания.“
Other important points:
- Interest on interest (anatocism) is in principle not owed. Interest is calculated only on the principal.
- Statutory interest is not the same as the annual percentage rate of charge (ГПР) on quick loans. It is compensation for delay set by law, not the price of a loan.
- For debts to the state (taxes, social security contributions, health insurance contributions) the state itself charges statutory interest on the overdue amount.
Frequently asked questions
What is statutory interest?
It is the default interest a debtor owes by law when they do not pay a money debt on time. Its amount is set by a decree of the Council of Ministers, not by the parties to the contract.
How much is statutory interest for 2026?
For the first half of 2026 the annual rate is about 10.15% (ECB main refinancing rate 2.15% plus 8 percentage points). The rate is reviewed on 1 January and 1 July each year.
From which day does default interest run?
From the day of the delay. If a due date was agreed, interest runs immediately after it. If there is no deadline, it starts to run from the day you invite the debtor in writing to pay.
Can I claim interest on a loan to a friend?
Yes, if the loan has fallen due and your friend is slow to repay it. Even without an express agreement on interest, statutory default interest is owed from the moment you invite them to return the sum.
Do you have a specific case with an overdue debt? You can ask Pravko and get information in plain language, with links to the exact texts of the law. For debts to the state, see also our article on checking your debts to НАП, and for other financial calculations, our tax calculator.
Ask Pravko and get an answer with citations from the law.
⚠️ Important
Pravko provides legal information, but it does not replace advice from a lawyer. For important legal matters, consult a licensed lawyer.
