Payments
Form Z-04
Late-payment interest calculator
Checked on your device
Explanation
Late-payment interest in three steps
Enter the amount
The amount of the invoice still unpaid, as on the invoice.
Choose the due date
The due date on the invoice, or the date you received it if nothing was agreed: it is then due 30 days later.
Read the interest
Per half-year the days, the rate and the interest, with the 40 euro and the total to copy.
At the counter
Good to know
Which law is this based on?
The Act of 2 August 2002 on combating late payment in commercial transactions. Interest runs by law from the day after the due date (article 5) and a fixed compensation of 40 euro is due per invoice (article 6).
What is the rate?
The European Central Bank’s rate for its main refinancing operations plus 8 percentage points, rounded up to the next half point. The Minister of Finance publishes it every half-year. A contract may set another rate: choose Contract then.
Does this apply to a private person?
No. Debts of consumers follow other rules (book XIX of the Code of Economic Law): a free first reminder, a 14-day term and other caps. This tool does not work those out.
Sources
What this tool relies on, with the date we checked it.
- GovernmentInterestvoet bij betalingsachterstand in handelstransacties (art. 5 wet van 2 augustus 2002), fiche per semester
- GovernmentBetalingsachterstand: wettelijke rentevoeten per lidstaat
Texts reviewed on 21 October 2026
Zegel checks and calculates, but gives no legal or tax advice. If in doubt, ask your accountant or the relevant authority.
For making invoices and keeping track of receipts, there’s Bureel, nealvdv’s business apps.
Payments
In the same drawer
- Z-01Check an IBANIs the account number right? With the bank shown for Belgian numbers.
- Z-02Structured communicationMake or check a +++123/4567/89002+++, in batches too.
- Z-03Make a payment QR codeA QR code your banking app can read: name, IBAN, amount and reference already filled in.
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