Invoice is not paid without a written contract: which records count

The technical question is when a claim becomes enforceable and which ancillary claims arise. The basis is the due date, default and the contractual agreement, supplemented by the statutory rules on default interest and recovery costs.

This overview does not replace legal advice in the individual case. It does show which points should be settled before any escalation. When an invoice stays unpaid, proof of delivery and of the invoice content is the first point to be checked. Small improvements here work through the entire receivables portfolio.

What needs checking is the conclusion of the contract, the service rendered, a proper invoice and the payment term. Only when this chain is unbroken do the consequences of default apply. Against consumers, the notice about the 30-day rule is added.

The invoice itself must contain the mandatory details so that it can be verified. Faulty invoices hand the debtor a convenient argument for holding back. Unpaid invoices often have a formal cause: a missing purchase order number, the wrong recipient or an unclear description of services. The thematic core stays the same: which records count.

Interest is calculated to the day from the onset of default on the outstanding amount. The applicable base rate plus the statutory margin is decisive. Where default runs past an adjustment date, the period is calculated in sections.

Partial payments are recorded with their date and reduce the interest amount from the day of receipt. Without that allocation, differences arise that have to be explained later. The more precisely an invoice describes the service delivered, the harder it is to delay payment with follow-up questions. That keeps the case understandable for colleagues with no prior knowledge of it.

Typical risks arise less from legal questions than from process gaps. These include incomplete invoices, partial payments that were never allocated, outdated address data and a tone that escalates too early and reduces willingness to pay. A short note in the system replaces any later reconstruction from memory.

Equally critical: receivables left unmentioned out of consideration for the customer relationship. The amount does not disappear, but the default risk rises. A brief confirmation of receipt from the customer saves a great deal of later discussion. Everything else is subordinate to this goal: which records count.

The practical consequence is changed payment behaviour. Customers who know that deadlines are monitored and default consequences are calculated pay earlier on average, without any dispute arising.

At the same time the documentation effort grows. Automating it pays off; handling it manually erodes the benefit quickly. For recurring services, a consistent invoice structure prevents queries from arising in the first place. The effort is one-off; the benefit repeats with every case.