# UBL-SR-45

> Due Date shall occur maximum once

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/ubl-sr-45

## Official rule text

Due Date shall occur maximum once

## Why did my invoice fail UBL-SR-45?

The Payment due date (BT-9) states when the invoice amount is due for payment. In UBL it is carried as cac:PaymentMeans/cbc:PaymentDueDate, and EN 16931 permits at most one due date per invoice. Multiple due dates would make the single amount due to be paid (BT-115) ambiguous.

## Common causes

- cbc:PaymentDueDate is present in more than one cac:PaymentMeans element.
- A duplicated PaymentMeans block was created for alternative payment methods, each repeating the due date.
- Installment logic incorrectly emitted several PaymentDueDate values in one invoice.

## How do I fix it?

```
Keep the due date in a single place: <cbc:PaymentDueDate>2026-08-01</cbc:PaymentDueDate> in one cac:PaymentMeans, and remove it from any others.
```