Customer breaks a payment promise: what the promise means and when to stop waiting

What does it mean when a customer promises to pay and then doesn’t?

“The transfer goes out on Friday.” Friday passes, the account stays empty. A week later: “Early next month, definitely.” This is a typical situation in which businesses wait too long. The customer responds, is friendly and disputes nothing. That is exactly why a reminder feels impolite.

Legally, the situation is clearer than the feeling. A promise made only by the customer changes nothing about the due date. The invoice was due on the agreed date and remains due. The customer is still in default and interest keeps running. The promise even helps you: anyone who writes that they will pay the invoice admits that they owe it.

This guide covers the stage between invoice and debt collection in which the customer keeps putting you off. If your customer does not respond at all, start with the guide Customer not paying: what businesses can do now.

How to proceed: reply to every promise in writing and state that the invoice remains due.

Announcement or new agreement: what has the customer really given you?

What matters is whether only the customer announces something or whether you both agree on something new. An announcement leaves your claim unchanged. An agreement on a later date is a deferral of payment (Stundung): until the new date, payment is no longer due and late-payment interest for that period does not accrue. A deferral often arises unintentionally, through your own reply.

If you really want to accommodate the customer, agree on instalments in writing, with fixed amounts, fixed dates and the rule that the entire remaining balance becomes due at once if an instalment is missed. The instalment agreement template shows how this looks.

How to proceed: include the sentence “The invoice remains due and statutory late-payment interest continues to accrue” in your reply to a promise. That way, no deferral arises by accident.

What does the promise do to late-payment interest and limitation?

The promise is evidence. In both countries it restarts the limitation period if it clearly refers to the specific claim, in Germany, however, only once the period is already running. Different rules apply to interest and default.

Austria

Under the Austrian Civil Code (ABGB), the debtor is in default as soon as they miss the payment date set by contract or law. If no date is set, a formal demand (Einmahnung) triggers default. Between businesses, late-payment interest under the Commercial Code (UGB) is 9.2 percentage points above the base rate, plus a flat fee of 40 euros for recovery costs. Claims for goods and services supplied in the course of business become time-barred after three years. If the debtor expressly or tacitly acknowledges the creditor’s right, limitation is interrupted and starts again. The Supreme Court (OGH) accepts any conduct that clearly shows the intention to acknowledge the debt. A promise to pay a specific invoice meets this test.

Germany

Under the German Civil Code (BGB), the debtor goes into default through a reminder after the due date, and without a reminder if the contract sets a calendar date. At the latest, the debtor is in default 30 days after the due date and receipt of the invoice; for consumers only if the invoice points this out. Late-payment interest is 9 percentage points above the base rate between businesses and 5 percentage points with consumers. Since 1 July 2026 the base rate has been 1.52 per cent, giving 10.52 and 6.52 per cent. Against businesses, the flat fee of 40 euros is added. Limitation starts again if the debtor acknowledges the claim by a payment on account, an interest payment or in any other way. A written promise to pay is such an acknowledgement. This only takes effect once limitation has begun: if the promise falls in the year in which the claim arose, the period still starts at the end of that year. An agreed deferral additionally suspends limitation while it runs.

How to proceed: keep every promise in its original form, meaning the e-mail, letter or a screenshot of the message showing date and sender. Confirm a promise made by phone by e-mail on the same day.

How do you follow up after the first missed date?

Do not wait to see whether the money might still arrive. Follow up on the first working day after the missed date, in writing and with a specific date. Ask for proof of payment if the customer claims to have already transferred the money. “The money is on its way” is not information; a payment confirmation with an execution date is.

Template for following up on a broken promise

Subject: Invoice R-2026-118 for EUR 4,200.00, your promise to pay of 16 October 2026

Dear Mr Berger,

On 16 October you promised to transfer the amount of invoice R-2026-118 by 23 October. To date, no payment has reached our account. If you have already made the transfer, please send us the payment confirmation. Otherwise, we expect the outstanding amount of EUR 4,200.00 in our account IBAN [your IBAN] by 6 November 2026 at the latest.

The invoice has been due since 2 October, and statutory late-payment interest continues to accrue. If no payment is received by 6 November, we will hand the claim over to a collection agency.

Kind regards

Adjust names, amounts and dates. Always give a calendar date rather than “within one week”, so there is no dispute about when the period starts. If you need a formal reminder including interest, the payment reminder generator creates a template.

How to proceed: send the follow-up by e-mail and enter the final deadline in your calendar straight away.

Which warning signs show that the stalling is systematic?

A single missed date can be an oversight. Several of the following signs together are not:

• The second promised date passes without payment and without a message.
• “The transfer has gone out”, but there is no proof and no transaction reference.
• Small, irregular partial payments arrive that were never discussed.
• The contact person changes or can only be reached via voicemail.
• A complaint appears only after you have set the final deadline.
• The customer asks for instalments but names neither amounts nor dates.
• Direct debits bounce or other suppliers report the same.

If you suspect insolvency, check the official insolvency notices: in Austria the Edicts File (Ediktsdatei) of the judiciary, in Germany insolvenzbekanntmachungen.de. If insolvency proceedings have been opened, file the claim in the proceedings instead of sending further reminders.

How to proceed: if two or more of these signs appear, do not grant any more time and set the final deadline.

When is enough enough? A worked example

The clearest rule is this: one promise is a chance. The second broken promise ends your patience. After that comes one final date in writing and, once it has passed, the handover, without a third round.

Example: A wholesaler in Germany supplies a restaurant business. The order provides for payment by 2 October 2026; the invoice is for 4,200 euros. On 16 October the customer promises by phone to pay by 23 October, and the wholesaler records the promise by e-mail, adding that the invoice remains due. Nothing arrives. On 26 October the wholesaler follows up and sets a final deadline of 6 November. The customer writes: “Early next week.” That passes too. On 16 November the wholesaler hands over the claim.

Because the payment date was fixed by calendar in the contract, the customer has been in default since 3 October without any reminder being required. Up to 16 November that is 45 days. At 10.52 per cent, this gives 4,200 euros times 10.52 per cent times 45 divided by 365, which is 54.47 euros of interest. The flat fee of 40 euros is added. The amount outstanding is therefore 4,294.47 euros. The two promises do not change limitation here: they fall in the year in which the claim arose, and in Germany the period only starts at the end of 2026 anyway. As evidence of default and of the claim, they are still valuable. In Austria, between businesses you calculate 9.2 percentage points above the base rate; the late-payment interest calculator gives you the amount.

How to proceed: decide for your business after how many broken promises a claim is handed over, and apply this rule to every customer.

When is it worth handing over to a collection agency, and how does it work?

Handing over is worthwhile as soon as the claim is due, the customer does not dispute the amount and the promises lead nowhere. That is the typical staller: they dispute nothing, they just do not pay. If the customer suddenly raises a defect, clarify that first. No reputable collection agency takes on disputed claims.

incaseof.law is a debt collection agency licensed in Austria and registered in Germany. It accepts due, undisputed claims with documented payment default. The handover takes place online in the client portal: register, enter the debtor, amount and due date, upload the invoice and supporting documents. Upload the promises and your follow-up at the same time; they document default and acknowledgement. There is no minimum volume. The case team decides on the reminder stages. In Austria, the case team recommends a payment-order claim (Mahnklage), but it is only filed after your approval. In Germany, court proceedings such as a court payment order (Mahnbescheid) are only initiated after your approval; the case team clarifies the procedural route and any representation required with you case by case. There are no automatic court filings.

For the staller, one point matters in particular: instead of making new promises, the debtor can apply for an instalment plan in the debtor portal. It is accepted according to fixed rules that are the same for everyone. You receive 100 per cent of the principal claim, and the defaulting debtor bears the costs of default within the limits permitted by law. In regular out-of-court collection there are no costs from incaseof.law, even if the debtor does not pay, and no success fee on your principal claim. Court fees and, in Austria, MANZ transmission fees only arise once you approve court proceedings. Collection and duration are not guaranteed.

How to proceed: use the page Customer not paying to find the right next step, and hand the case over via Submit a claim as soon as your final deadline has passed.