Guide

E-invoice validation rules explained

Validators report errors as rule IDs such as BR-DE-15 or BR-CO-15. For each rule, this page explains what it requires, why it typically fails, what the correct XML looks like and how to fix the error in C#.

An invoice with error messages? Check it in the online validator – every explained rule in the result links straight to its page.

XRechnung (German national rules)

BR-DE-1 Payment instructions (BG-16) missing

Every XRechnung needs payment instructions with a payment means type code (BT-81).

BR-DE-2 Seller contact (BG-6) missing

XRechnung requires a seller contact point with phone number and e-mail address.

BR-DE-15 Buyer reference / Leitweg-ID (BT-10) missing

Every XRechnung needs a buyer reference – for German public authorities the Leitweg-ID.

BR-DE-16 Seller VAT ID or tax number missing

With VAT categories such as S, Z, E or AE, the seller's VAT ID or tax number must be present.

BR-DE-18 Cash discount (Skonto) in BT-20 badly formatted

Cash discounts go into the payment terms in a fixed syntax: #SKONTO#TAGE=14#PROZENT=2.00#.

BR-DE-21 Invalid specification identifier (BT-24) Warning

BT-24 must carry the XRechnung identifier – otherwise the invoice is not recognised as an XRechnung.

Calculation rules

BR-CO-10 Sum of line net amounts (BT-106) is wrong

BT-106 must equal the exact sum of all invoice line net amounts (BT-131).

BR-CO-15 Total with VAT (BT-112) ≠ net total + VAT

The gross total must be exactly the net total plus the total VAT amount.

VAT categories

BR-S-08 VAT taxable amount (BT-116) per rate is wrong

For each VAT rate, the taxable amount must equal the sum of the lines with that rate.

BR-AE-10 Reverse charge without exemption reason

Reverse charge needs the exemption reason “Reverse charge” or the code VATEX-EU-AE.

More rules will follow. Your message is not covered yet? Let us know via the contact page.