# PEPPOL-EN16931-R111

> End date of line period MUST be within invoice period.

Checked against Peppol BIS Billing 3.0 2026.5

Canonical: https://einvoicecheck.eu/rules/peppol-en16931-r111

## Official rule text

End date of line period MUST be within invoice period.

## Why did my invoice fail PEPPOL-EN16931-R111?

The end date of an invoice line's billing period (BT-135) must fall within the document-level invoicing period (BT-73 to BT-74). A line period cannot end before the invoice period starts or after it ends, keeping each line period inside the overall invoice period.

## Common causes

- A line InvoicePeriod/EndDate is later than the header InvoicePeriod/EndDate.
- A line period end precedes the header period StartDate because of swapped or mistyped dates.
- The header period was truncated while a line still references the original, longer period.

## How do I fix it?

```
Ensure the line end is inside the header window, e.g. header 2026-01-01 to 2026-01-31 and line <cac:InvoicePeriod><cbc:EndDate>2026-01-25</cbc:EndDate></cac:InvoicePeriod>.
```