Validation rules

BR-13 — EN 16931 rule

The invoice total without VAT (BT-109) is missing from the document totals.

Rule

BR-13 — official EN 16931 / XRechnung rule

Severity

error

Business term

BT-109 — Total without VAT

Field in your JSON

invoice.totals.net

Detected by

tier 3 — KoSIT validator (authoritative)

Reachability

Only reachable when validating your own XML — normbill-generated documents cannot trigger it

The serializer always writes BT-109 from its own computed totals.

How to fix it

Add cbc:TaxExclusiveAmount to cac:LegalMonetaryTotal.

Related rules

• BR-CO-13 — Supplied totals.net does not equal the sum of line nets minus document allowances plus document charges.
• BR-DEC-12 — totals.net (BT-109) has more than 2 decimal places — EN 16931 allows at most 2.
• BR-12 — The sum of invoice line net amounts (BT-106) is missing from the document totals.
• BR-14 — The invoice total with VAT (BT-112) is missing from the document totals.
• BR-11 — The buyer address has no country code (BT-55).
• BR-15 — The amount due for payment (BT-115) is missing from the document totals.

Official sources

• XRechnung specification (KoSIT / xeinkauf.de)
• KoSIT validator on GitHub and the XRechnung validator configuration

Every 422 from the API lists the rule id, the path in your request JSON, a plain-language message and a suggested fix — see the docs overview for the report format.

Or try it live: drop any XRechnung XML on the free validator — same KoSIT-backed report, no account.