What does AI actually do in dunning?

Three things reliably: watch open invoices so a due date is never missed, draft the reminder or formal notice, and send the escalation stages on schedule. What it does not do is the legal assessment — whether default has occurred is set out in § 286 BGB and is arithmetic, not judgement.

When is a customer automatically in default?

Under § 286 (3) BGB at the latest 30 days after BOTH the due date and receipt of the invoice — it takes both events, not just the invoice date. Against a consumer this route only works if the invoice expressly pointed out that consequence. A reminder issued after the due date triggers default immediately (§ 286 (1)), so the 30 days are a backstop, not a waiting period.

May an AI send payment reminders automatically?

Technically yes, and that is the most useful part of automating this. The limit sits elsewhere: automatic dispatch must not assert legal positions that were never checked — charging default interest or the €40 flat fee against a consumer, for instance. Set the escalation stages deliberately once, then let them run.

What default interest may I charge?

In pure B2B dealings 9 percentage points above the base rate, currently 10,52 %. Where a consumer is involved it is 5 points, so 6,52 %. The 40 € flat fee under § 288 (5) BGB exists only in the B2B case.

Payment reminders

AI in dunning: what it takes over — and what stays a rule

In dunning, AI is genuinely good at two things: watching dates and drafting text. The third thing most people expect — deciding whether your customer is actually in default — it cannot do better than a spreadsheet, because that is not a judgement call. It is a rule in § 286 BGB.

What "AI dunning" actually means in practice

The term rarely hides a language model reasoning about law. It hides an automation that takes over four tasks — and those four are precisely the ones freelancers otherwise forget or put off:

Watch open invoices and spot the due date — not the invoice date, which is a different day
Stage the escalation: reminder, first notice, final notice, each with its own interval
Draft the text — friendly the first time, firm the third, without you rethinking it three times
Send it, so you never have to pick the moment you can bring yourself to do it

The fourth point is the real one. Most unpaid invoices stay open not because someone refuses to pay, but because nobody followed up. Automation solves exactly that problem — and only that one.

The part that needs no AI: default is a rule

Whether a customer is in default is not estimated. § 286 BGB knows three routes there, and every one of them is computable:

First, you send a reminder after the due date — default starts immediately (para. 1). Second, you agreed a calendar date — then no reminder is needed at all (para. 2 no. 1). Third, 30 days have passed — after both the due date and receipt of the invoice, not from the invoice date (para. 3).

The third route carries a catch that automations like to miss: against a consumer it only applies if the invoice expressly pointed out that consequence. Without that sentence the 30-day automatic route does not run, and you need the reminder from route one.

What you may charge — and where automation gets dangerous

Default interest tracks the base rate, which changes on 1 January and 1 July. Since 1 July 2026 it stands at 1,52 %. That gives 10,52 % between businesses (9 points, § 288 (2) BGB) and 6,52 % as soon as a consumer is involved (5 points, para. 1).

This is precisely where blind automation gets expensive. The 40 € flat fee under § 288 (5) BGB exists only in the B2B case. A system that staples it to every overdue invoice asserts a claim against private customers that does not exist. That is not an AI problem — it is a configuration problem, which is why "business or private" belongs in the customer record, not in the reminder text.

The full calculation with a worked example and a template is in the post on default interest, and the wording for each stage is in the guide to writing reminders.

Where the automation should stop

One thing should never happen automatically: the final stage. A reminder and a first notice are routine and can run on their own. From the point where you threaten collection, court proceedings or the end of the working relationship, you are deciding about a business relationship — and a person who knows that customer should make that call. Good automation is judged not by how much it takes over, but by where it stops to ask.

Last updated 3 September 2026. Verified against § 286 and § 288 BGB (§ 286 BGB, gesetze-im-internet.de); base rate verified on 28 August 2026 with Deutsche Bundesbank.