What does BR-CO-10 mean?

Why error BR-CO-10 appears in an e-invoice and how to check the line net amount calculation.

BR-CO-10 — Sum of invoice line net amounts doesn't add up

What it means

The sum of invoice line net amounts doesn't add up. The invoice's total line net amount (BT-106) must equal the sum of all individual line net amounts (BT-131) — the validator adds up the lines and compares them to the stated total. This field is the basis for every calculation that follows in the invoice (discounts, charges, VAT base), so the validator checks it first.

Common causes

Rounding. Each line is rounded individually while the total is calculated from ungrouped values (or the other way around) — the gap is usually a few cents.
A line was added or removed after the total was calculated. The software calculates the total first, the user then edits a line, and the total isn't recalculated automatically.
A line-level discount or charge isn't reflected in the line amount. If the discount is only applied visually (in the PDF view) but doesn't show up in each line's LineExtensionAmount value.
Negative amounts on a credit note. Some systems miscalculate the total by ignoring the negative sign on one or more lines.

How to fix it

Check each line's amount (quantity × price, including any line-level discounts and charges) and confirm that the total (LineExtensionAmount at document level) really is the sum of every line — not rounded separately or left unrecalculated after a line was edited.

Examples

Wrong: lines 50.00 + 30.00, but the total is stated as 90.00. Correct: lines 50.00 + 30.00, total 80.00.

Wrong (rounding): three lines of 33.33, total stated as 100.00 (33.33 × 3 = 99.99, not 100.00). Correct: total 99.99, or the line amounts adjusted so they add up to exactly 100.00.

How this differs from BR-CO-13 and BR-CO-15

BR-CO-10 only checks the sum of the lines against their own total. BR-CO-13 checks the next step — the total without VAT after document-level discounts and charges. BR-CO-15 checks the total with VAT. If an invoice has several errors at once, start with BR-CO-10 — the other two often resolve themselves once the line sum is correct.