Payment reminders
Calculating default interest: formula, current rate and a reminder template
The current default-interest rate
The statute names no fixed percentage. It names a margin on top of the base rate under § 247 BGB, which the Bundesbank publishes and resets twice a year, on 1 January and 1 July. Copying a rate from an older article is therefore almost always wrong.
| Case | Legal basis | Rate p.a. |
|---|---|---|
| Germany, a consumer is involved | § 288 Abs. 1 BGB (5 %-Punkte) | 6,52 % |
| Germany, business to business | § 288 Abs. 2 BGB (9 %-Punkte) | 10,52 % |
| Austria, business to business | § 456 UGB (9,2 %-Punkte) | 10,73 % |
| Austria, otherwise | § 1000 ABGB | 4,00 % |
The two base rates are not identical: Germany is at 1,52 %, Austria at 1,53 % (both as of 1 July 2026). They are calculated differently, so never apply the German figure to an Austrian claim. Sources: Deutsche Bundesbank and WKO.
The formula, worked through
Default interest is an annual rate, so a shorter period is prorated by day:
Example: a B2B invoice for 2.400 € is 30 days overdue. At 10,52 % that is 2.400 € × 0,105 × 30 ÷ 365 = 20,75 € in interest, plus the 40 € flat fee.
Count from the day after default begins up to and including the day of payment. If the period straddles 1 January or 1 July, split it: each part uses the base rate that applied at the start of that half-year.
When you may start charging
Interest does not run from the invoice date but from the moment of default. Three routes get you there:
- You send a reminder after the due date. Default begins when it arrives — one is enough; the widely believed "three reminders" rule is not in the statute.
- You agreed a fixed payment date ("payable by 15 September"). Default then starts when that date passes, with no reminder needed.
- Thirty days after the invoice was received, default begins automatically (§ 286 Abs. 3 BGB) — against consumers only if you said so on the invoice itself.
Templates to copy
Stage one stays friendly and mentions no interest — most payments arrive here. Stage two puts a number on the interest and the flat fee. Replace the bracketed placeholders.
Betreff: Zahlungserinnerung zur Rechnung [Rechnungsnummer] Sehr geehrte Damen und Herren, unsere Rechnung [Rechnungsnummer] vom [Rechnungsdatum] über 2.400 € war am [Fälligkeitsdatum] zur Zahlung fällig. Ein Zahlungseingang ist bislang nicht zu verzeichnen. Wir bitten Sie, den offenen Betrag bis zum [neues Datum, i. d. R. 7–14 Tage] auf folgendes Konto zu überweisen: [Kontoinhaber] IBAN: [IBAN] BIC: [BIC] Verwendungszweck: [Rechnungsnummer] Sollte sich Ihre Zahlung mit diesem Schreiben überschnitten haben, betrachten Sie es bitte als gegenstandslos. Mit freundlichen Grüßen [Name]
Betreff: Mahnung zur Rechnung [Rechnungsnummer] Sehr geehrte Damen und Herren, trotz unserer Zahlungserinnerung vom [Datum] ist die Rechnung [Rechnungsnummer] vom [Rechnungsdatum] über 2.400 € weiterhin offen. Sie befinden sich seit dem [Datum des Verzugseintritts] in Zahlungsverzug. Wir stellen Ihnen daher in Rechnung: Hauptforderung: 2.400 € Verzugszinsen (10,52 % p. a., 30 Tage): 20,75 € Pauschale nach § 288 Abs. 5 BGB: 40 € ------------------------------------------------ Gesamtbetrag: 2.460,75 € Wir bitten um Überweisung des Gesamtbetrags bis zum [Datum] auf das unten genannte Konto. Mit freundlichen Grüßen [Name]
For clients abroad, the same stages in English are in payment reminders in English. The full process, from first contact to a court order, is in the reminder guide.
Three mistakes that cost money
- Using the wrong margin. The 9 points apply only when NO consumer is involved on either side. As soon as a private client is, it drops to 5 — claim too much and you have to walk it back.
- Using a stale base rate. It changes on 1 January and 1 July; an article from a year ago will name a different figure.
- Charging the 40-euro flat fee to a consumer. It exists for business dealings only.
Last updated 9 October 2026. Base rates verified on 28 August 2026 against Deutsche Bundesbank and WKO.