What is the current German default-interest rate?

The base rate under § 247 BGB has been 1,52 % since 1 July 2026. That makes 10,52 % per year when no consumer is involved (§ 288 Abs. 2 BGB) and 6,52 % when one is (§ 288 Abs. 1 BGB). In Austria, business-to-business default interest is 10,73 % (§ 456 UGB).

How do I calculate default interest for a period?

Outstanding amount × rate × days in default ÷ 365. Example: 2.400 € at 10,52 % for 30 days comes to 20,75 €. Count from the day after default begins until the day of payment.

When may I start charging default interest?

Once the debtor is in default. That happens when you send a reminder after the due date — or automatically 30 days after the invoice was received (§ 286 Abs. 3 BGB). Against consumers, the automatic 30-day rule only applies if you pointed it out on the invoice itself. An agreed fixed payment date also triggers default without any reminder.

What is the 40-euro flat fee?

When a business is in default you may claim a flat 40 € on top of the interest (§ 288 Abs. 5 BGB). It applies in business dealings only — never against consumers — and is offset against any legal-costs claim you make later. Austria has an identical flat fee for collection costs.

Reminder or "Mahnung" — what is the difference?

Legally nothing: both count as a reminder under § 286 BGB once they demand payment after the due date. The difference is tone only. Nor is there any duty to send three reminders — a single one is enough to trigger default.

Payment reminders

Calculating default interest: formula, current rate and a reminder template

German default interest is 9 percentage points above the base rate when no consumer is involved, and 5 points when one is. With the base rate at 1,52 % (in force since 1 July 2026) that means 10,52 % and 6,52 % per year. In Austria, business-to-business default interest is 10,73 %.

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:

Outstanding amount × rate × days in default ÷ 365

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.

Payment reminder (stage 1)

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]

Reminder with interest (stage 2)

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 28 August 2026. Base rates verified on 28 August 2026 against Deutsche Bundesbank and WKO. This article is general information and does not replace legal or tax advice.