# BR-30 > If both Invoice line period start date (BT-134) and Invoice line period end date (BT-135) are given then the Invoice line period end date (BT-135) shall be later or equal to the Invoice line period start date (BT-134). Checked against Peppol BIS Billing 3.0 2026.5 Canonical: https://einvoicecheck.eu/rules/br-30 ## Official rule text If both Invoice line period start date (BT-134) and Invoice line period end date (BT-135) are given then the Invoice line period end date (BT-135) shall be later or equal to the Invoice line period start date (BT-134). ## Why did my invoice fail BR-30? When an Invoice line has its own period with both a line period start date (BT-134) and end date (BT-135), the end date must be equal to or later than the start date. This keeps the service/delivery period reported per line chronologically consistent. ## Common causes - Line-level start and end dates swapped in the line mapping - Line period copied incorrectly from a document-level period - One of the two dates missing a value and falling back to an earlier default ## How do I fix it? ``` Set the line period so EndDate >= StartDate: ...2026-02-012026-02-28 ```