Late payment interest calculator for overdue German invoices
Enter the amount, the first day of default and the customer type. The calculator uses the base rate that applied in each period and allocates part payments in the statutory order.
This calculator applies German law (§§ 247, 288 BGB) and the base rate published by the Deutsche Bundesbank. Claims under Austrian, Swiss or other law follow different rates and different rules.
Enter the amount, the first day of default and the end date to see the result.
Which rate applies to me?
The rate depends solely on who your customer is — not on how large the invoice is or how long it has been outstanding.
| Your customer | Annual rate | Calculation | Law |
|---|---|---|---|
| Company, association, public body, other self-employed people | 10.52 % | 9 percentage points above the base rate | § 288 Abs. 2 BGB |
| Private individual | 6.52 % | 5 percentage points above the base rate | § 288 Abs. 1 BGB |
Careful with "percentage points": nine percentage points above 1.52 percent is 10.52 percent, not 1.66 percent. The base rate is added, not multiplied.
What counts is whether your customer bought privately or for their business. An electrician ordering a heating system for their own home is a private customer. The same electrician ordering cable for a building site is a business customer.
Current base rate: 1.52 %
The base rate has stood at 1.52 % since 1 July 2026. The Deutsche Bundesbank sets it twice a year, on 1 January and 1 July. The next possible change is 1 January 2027.
If your period of default runs across one of these dates, the two sections carry different rates. The calculator above handles that automatically.
| In force from | Base rate | Interest B2B | Interest B2C |
|---|---|---|---|
| 01/07/2026 | 1.52 % | 10.52 % | 6.52 % |
| 01/01/2026 | 1.27 % | 10.27 % | 6.27 % |
| 01/07/2025 | 1.27 % | 10.27 % | 6.27 % |
| 01/01/2025 | 2.27 % | 11.27 % | 7.27 % |
| 01/07/2024 | 3.37 % | 12.37 % | 8.37 % |
| 01/01/2024 | 3.62 % | 12.62 % | 8.62 % |
| 01/07/2023 | 3.12 % | 12.12 % | 8.12 % |
| 01/01/2023 | 1.62 % | 10.62 % | 6.62 % |
| 01/07/2022 | -0.88 % | 8.12 % | 4.12 % |
When does interest start running?
Counting starts the day after default begins — and default begins later than most people think. A payment deadline alone is not enough.
Default starts when you have sent a reminder, when the invoice names a fixed date ("payable by 30 September 2026"), or at the latest 30 days after the invoice fell due and was received.
For private customers the 30-day rule only applies if you pointed out that consequence in the invoice (§ 286 Abs. 3 BGB). Without that note you have to send a reminder.
In detail, with examples: Late payment interest in Germany: rate, formula and example
Part payments: what gets settled first?
If your customer transfers less than the full claim, costs and interest come off first — only the remainder reduces the invoice itself. So the principal stays open longer than the customer expects, and interest keeps running on it.
That is what § 367 Abs. 1 BGB says: a payment that does not settle the whole debt is applied first to costs, then to interest and last to the principal.
The calculator follows that order. Enter each part payment with its date and amount.
Frequently asked questions
Is the calculator free?
Yes, with no sign-up and no registration. It runs in your browser; the amounts you enter never leave your device.
Does this also apply to Austria or Switzerland?
No. The calculator implements German law (§§ 247, 288 BGB) and the base rate of the Deutsche Bundesbank. Austria and Switzerland use different rates and different foundations.
Can I reuse the result?
Yes. Below the result you get a ready-made text block for your reminder, with period, rate and amount. You can copy and paste it.
Why do I get a different figure than another calculator?
Usually for one of two reasons. First, many calculators apply a single rate throughout, even when the period runs across 1 January or 1 July. Second, there are two ways to count a year: actual calendar days (365 or 366) and the commercial 360 days. This calculator uses actual calendar days, because the BGB does the same. The difference is around one percent.
If you are chasing payments regularly, Easy Invoice keeps track for you: open items at a glance, reminder levels and deadlines running along.
This calculator provides general information and does not replace legal or tax advice. No warranty is given for correctness in an individual case.