E-invoice validation rules, explained

The 103 business rules our validator runs on XRechnung, ZUGFeRD, Factur-X and other EN 16931 invoices: what each means, where the field is in the XML, and the fix.

XRechnung rules (BR-DE)

Rule	What it requires
`BR-DE-1`	An XRechnung must contain payment instructions.
`BR-DE-2`	An XRechnung must contain the seller contact group.
`BR-DE-3`	The seller's city must be given.
`BR-DE-4`	The seller's post code must be given.
`BR-DE-5`	The seller's contact point (a name or department) must be given.
`BR-DE-6`	The seller's contact telephone number must be given.
`BR-DE-7`	The seller's contact e-mail address must be given.
`BR-DE-8`	The buyer's city must be given.
`BR-DE-9`	The buyer's post code must be given.
`BR-DE-14`	Each VAT breakdown row must give its VAT rate.
`BR-DE-15`	The buyer reference must be given.
`BR-DE-16`	When a VAT category S, Z, E, AE, K, G, L or M is used, the seller's VAT identifier or tax registration number must be given.
`BR-DE-17`	The invoice type code should be one of 326, 380, 384, 389, 381, 875, 876 or 877.
`BR-DE-19`	With payment means code 58 (SEPA credit transfer) the payment account should be a correct IBAN.
`BR-DE-21`	The specification identifier should be the XRechnung identifier.
`BR-DE-23-a`	When the payment means code is a credit transfer (30 or 58), the credit transfer details must be given.
`BR-DE-27`	The seller's telephone number should contain at least three digits.
`BR-DE-28`	The seller's e-mail address should have exactly one @ with at least two characters on each side.

Mandatory fields (BR)

Rule	What it requires
`BR-01`	An invoice must have a specification identifier.
`BR-02`	An invoice must have an invoice number.
`BR-03`	An invoice must have an issue date.
`BR-04`	An invoice must have an invoice type code.
`BR-05`	An invoice must have a currency code.
`BR-06`	An invoice must contain the seller's name.
`BR-07`	An invoice must contain the buyer's name.
`BR-08`	An invoice must contain the seller's postal address.
`BR-09`	The seller's postal address must contain a country code.
`BR-10`	An invoice must contain the buyer's postal address.
`BR-11`	The buyer's postal address must contain a country code.
`BR-12`	An invoice must state the sum of the invoice line net amounts.
`BR-13`	An invoice must state the total amount without VAT.
`BR-14`	An invoice must state the total amount with VAT.
`BR-15`	An invoice must state the amount due for payment.
`BR-16`	An invoice must have at least one invoice line.
`BR-21`	Each invoice line must have a line identifier.
`BR-22`	Each invoice line must have an invoiced quantity.
`BR-23`	Each invoice line must have a unit of measure code for its quantity.
`BR-24`	Each invoice line must have a line net amount.
`BR-25`	Each invoice line must contain the item name.
`BR-26`	Each invoice line must contain the item net price.
`BR-27`	The item net price must not be negative.
`BR-45`	Each VAT breakdown row must have a taxable amount.
`BR-46`	Each VAT breakdown row must have a VAT amount.
`BR-47`	Each VAT breakdown row must have a VAT category code.
`BR-48`	Each VAT breakdown row must have a VAT rate, except when the invoice is not subject to VAT.
`BR-61`	When the payment means is a credit transfer (codes 30 and 58), the payment account identifier must be present.
`BR-62`	The seller's electronic address must have a scheme identifier.
`BR-63`	The buyer's electronic address must have a scheme identifier.

Sums and consistency (BR-CO)

Rule	What it requires
`BR-CO-04`	Each invoice line must have a VAT category code.
`BR-CO-09`	A VAT identifier must start with the two-letter country code of the member state that issued it (EL for Greece).
`BR-CO-10`	The sum of invoice line net amounts must equal the total of the line net amounts.
`BR-CO-13`	The total without VAT must equal the line total minus document allowances plus document charges.
`BR-CO-14`	The total VAT amount must equal the sum of the VAT amounts of the VAT breakdown rows.
`BR-CO-15`	The total with VAT must equal the total without VAT plus the total VAT amount.
`BR-CO-16`	The amount due must equal the total with VAT minus the paid amount plus the rounding amount.
`BR-CO-17`	The VAT amount of a breakdown row must equal its taxable amount times its rate, rounded to two decimals.
`BR-CO-18`	An invoice must have at least one VAT breakdown row.
`BR-CO-25`	When the amount due is positive, the payment due date or the payment terms must be present.
`BR-CO-26`	The seller must be identifiable: a seller identifier, a legal registration identifier or a VAT identifier must be present.

VAT categories (BR-S, BR-Z, BR-E, BR-AE, BR-IC, BR-G)

Rule	What it requires
`BR-S-01`	An invoice with a line in VAT category "Standard rated" (S) must have at least one VAT breakdown row for that category.
`BR-S-02`	An invoice with a "Standard rated" line must state the seller's VAT identifier or tax registration number.
`BR-S-05`	On a standard-rated line the VAT rate must be greater than zero.
`BR-S-08`	For each standard VAT rate, the taxable amount in the VAT breakdown must equal the sum of the net amounts of the lines with that rate.
`BR-S-09`	The VAT amount of a standard-rated breakdown row must equal its taxable amount times its rate.
`BR-S-10`	A "Standard rated" VAT breakdown row must not give a VAT exemption reason.
`BR-Z-01`	An invoice with a line in VAT category "Zero rated" (Z) must have exactly one VAT breakdown row for that category.
`BR-Z-02`	An invoice with a "Zero rated" line must state the seller's VAT identifier or tax registration number.
`BR-Z-05`	On a "Zero rated" line the VAT rate must be 0.
`BR-Z-08`	The taxable amount of the "Zero rated" VAT breakdown row must equal the sum of the net amounts of its lines.
`BR-Z-09`	The VAT amount of the "Zero rated" breakdown row must be 0.
`BR-Z-10`	A "Zero rated" VAT breakdown row must not give a VAT exemption reason.
`BR-E-01`	An invoice with a line in VAT category "Exempt from VAT" (E) must have exactly one VAT breakdown row for that category.
`BR-E-02`	An invoice with a "Exempt from VAT" line must state the seller's VAT identifier or tax registration number.
`BR-E-05`	On a "Exempt from VAT" line the VAT rate must be 0.
`BR-E-08`	The taxable amount of the "Exempt from VAT" VAT breakdown row must equal the sum of the net amounts of its lines.
`BR-E-09`	The VAT amount of the "Exempt from VAT" breakdown row must be 0.
`BR-E-10`	A "Exempt from VAT" VAT breakdown row must give a VAT exemption reason (text or code).
`BR-AE-01`	An invoice with a line in VAT category "Reverse charge" (AE) must have exactly one VAT breakdown row for that category.
`BR-AE-02`	An invoice with a "Reverse charge" line must state the seller's VAT identifier or tax registration number, and the buyer's VAT identifier.
`BR-AE-05`	On a "Reverse charge" line the VAT rate must be 0.
`BR-AE-08`	The taxable amount of the "Reverse charge" VAT breakdown row must equal the sum of the net amounts of its lines.
`BR-AE-09`	The VAT amount of the "Reverse charge" breakdown row must be 0.
`BR-AE-10`	A "Reverse charge" VAT breakdown row must give a VAT exemption reason (text or code).
`BR-IC-01`	An invoice with a line in VAT category "Intra-community supply" (K) must have exactly one VAT breakdown row for that category.
`BR-IC-02`	An invoice with a "Intra-community supply" line must state the seller's VAT identifier or tax registration number, and the buyer's VAT identifier.
`BR-IC-05`	On a "Intra-community supply" line the VAT rate must be 0.
`BR-IC-08`	The taxable amount of the "Intra-community supply" VAT breakdown row must equal the sum of the net amounts of its lines.
`BR-IC-09`	The VAT amount of the "Intra-community supply" breakdown row must be 0.
`BR-IC-10`	A "Intra-community supply" VAT breakdown row must give a VAT exemption reason (text or code).
`BR-G-01`	An invoice with a line in VAT category "Export outside the EU" (G) must have exactly one VAT breakdown row for that category.
`BR-G-02`	An invoice with a "Export outside the EU" line must state the seller's VAT identifier or tax registration number.
`BR-G-05`	On a "Export outside the EU" line the VAT rate must be 0.
`BR-G-08`	The taxable amount of the "Export outside the EU" VAT breakdown row must equal the sum of the net amounts of its lines.
`BR-G-09`	The VAT amount of the "Export outside the EU" breakdown row must be 0.
`BR-G-10`	A "Export outside the EU" VAT breakdown row must give a VAT exemption reason (text or code).

Decimals (BR-DEC)

Rule	What it requires
`BR-DEC-09`	The sum of line net amounts may have at most 2 decimals.
`BR-DEC-12`	The total without VAT may have at most 2 decimals.
`BR-DEC-13`	The total VAT amount may have at most 2 decimals.
`BR-DEC-14`	The total with VAT may have at most 2 decimals.
`BR-DEC-18`	The amount due may have at most 2 decimals.
`BR-DEC-19`	A VAT breakdown taxable amount may have at most 2 decimals.
`BR-DEC-20`	A VAT breakdown VAT amount may have at most 2 decimals.
`BR-DEC-23`	A line net amount may have at most 2 decimals.

This is a subset of the two standards: the rules a plain invoice with lines, VAT and a bank transfer can break. Rules about allowances and charges, attachments, card and direct-debit payments are not run.