BR-29: The invoicing period cannot end before it starts

What it means

When the invoice gives both a start date (BT-73) and an end date (BT-74) for the invoicing period, the end date must be on or after the start date. A one-day period has the same date twice.

Why it matters

The invoicing period tells the buyer and the tax authority when the goods or services were supplied, which can decide the VAT period. A period that ends before it starts is impossible, so the invoice is rejected.

How to fix it

Check the service or billing period on the invoice and swap or correct the dates. A common cause is a date typed in the wrong order, such as 03/04 read as 4 March instead of 3 April. If you build the XML yourself, the dates are in cac:InvoicePeriod (UBL) or ram:BillingSpecifiedPeriod (CII).

The rule as published

If both Invoicing period start date (BT-73) and Invoicing period end date (BT-74) are given then the Invoicing period end date (BT-74) shall be later or equal to the Invoicing period start date (BT-73).

Business terms: BT-73, BT-74

Where this rule applies