BR-16 — The invoice must have at least one line

What it means

The invoice must have at least one line (a good or a service). An invoice with no lines doesn't say what payment is being requested for.

How to fix it

Check that the invoice XML contains at least one InvoiceLine element. If the invoice is built from an order or quote, check that the line items actually made it into the export.

Example

Wrong: the invoice has no InvoiceLine elements. Correct: at least one <cac:InvoiceLine> block with a description, quantity, and amount.