BR-CO (EN 16931 calculation rules)

BR-CO rules ensure that all the totals on an invoice add up correctly.

Definition

In EN 16931, business rules are prefixed by their family. The BR-CO rules ("conditions" / cross-total calculations) verify the arithmetic consistency across the different levels of the invoice: lines, VAT breakdown and document totals.

What they check

• the sum of line net amounts (BT-131) must equal the sum of line net total (BT-106);
• the total without VAT (BT-109) plus the total VAT (BT-110) must equal the grand total (BT-112);
• the amount due for payment (BT-115) must equal the grand total minus prepaid amounts (BT-113) plus rounding (BT-114);
• for each VAT breakdown, the tax amount must match the taxable base times the rate.

Good to know

BR-CO checks are implemented in Schematron and run on receipt. A single rounding mismatch can fail validation. Calculations are generally performed to two decimals, and any document rounding difference must, where needed, be carried explicitly in BT-114.