EN 16931: All Required Fields of the European Invoice Standard
The European standard EN 16931 forms the foundation of all e-invoice formats in Germany and the EU. Anyone generating ZUGFeRD or XRechnung must comply with its required fields — otherwise the invoice will be rejected.
> Quick answer: EN 16931 defines over 160 business terms for e-invoices. Mandatory fields include invoice number (BT-1), date (BT-2), currency (BT-5), seller and buyer data, amount fields, and at least one invoice line item with quantity, price, and tax category.
What is EN 16931 and why is it relevant?
EN 16931 is the European standard for the semantic data model of an electronic invoice. It defines over 160 business terms (BT) and business term groups (BG) that can appear in an e-invoice.
The Growth Opportunities Act stipulates that only formats complying with EN 16931 qualify as e-invoices. Both ZUGFeRD (from profile EN 16931) and XRechnung comply with this standard.
Which fields are mandatory in the invoice header?
| BT | Name | Description |
|---|---|---|
| BT-1 | Invoice number | Unique identifier of the invoice |
| BT-2 | Invoice date | Issue date (format: YYYYMMDD) |
| BT-3 | Invoice type | TypeCode: 380 (invoice), 381 (credit note) |
| BT-5 | Currency code | ISO 4217, e.g., EUR |
Which seller data (BG-4) is mandatory?
| BT | Name | Description |
|---|---|---|
| BT-27 | Name | Company name of the seller |
| BT-31 | VAT ID | VAT identification number |
| BT-40 | Country code | ISO 3166-1 alpha-2, e.g., DE |
Which buyer data (BG-7) is mandatory?
| BT | Name | Description |
|---|---|---|
| BT-44 | Name | Company name of the buyer |
Which amount fields (BG-22) must be filled?
| BT | Name | Description |
|---|---|---|
| BT-106 | Line items total | Sum of all line item net amounts |
| BT-109 | Net amount | Invoice amount without tax |
| BT-110 | Tax amount | Total tax amount |
| BT-112 | Gross amount | Invoice amount including tax |
| BT-115 | Amount due | Amount due for payment |
Which line item fields (BG-25) are mandatory?
| BT | Name | Description |
|---|---|---|
| BT-126 | Line number | Unique line identifier |
| BT-129 | Quantity | Invoiced quantity |
| BT-130 | Unit | UN/ECE Rec 20 code (C62, HUR, DAY) |
| BT-131 | Line amount | Net amount of the line item |
| BT-146 | Unit price | Price per unit net |
| BT-151 | VAT category | S (Standard), E (Exempt), Z (Zero) |
| BT-153 | Item name | Description of the item |
For small businesses, tax category E (Exempt) with a 0% tax rate and the exemption reason under § 19 UStG applies.
How can I automatically check the required fields?
TaxLayer validates every generated invoice automatically against all mandatory BTs. You can additionally verify the result with the free ZUGFeRD & XRechnung Validator or the official KoSIT Validator.
Test the automatic validation for free: the first two conversions per month are available without a credit card — get started now.
Frequently asked questions
What is EN 16931?
EN 16931 is the European standard for the semantic data model of an electronic invoice. It defines over 160 business terms (BT) and groups (BG) that can appear in an e-invoice.
Which fields are mandatory in every e-invoice?
The most important required fields include: BT-1 (invoice number), BT-2 (date), BT-5 (currency), BT-27 (seller name), BT-44 (buyer name), BT-109 (net amount), and BT-112 (gross amount).
What data must be included in the invoice line items?
Each line item must contain: BT-126 (line number), BT-129 (quantity), BT-130 (unit), BT-131 (line amount), BT-146 (unit price), BT-151 (VAT category), and BT-153 (item name).
What is the difference between EN 16931 and XRechnung?
EN 16931 is the European base standard. XRechnung is a German CIUS (customization) that defines additional rules, e.g., the mandatory Leitweg-ID (BR-DE-01).
How do I check whether my e-invoice contains all required fields?
Use the free ZUGFeRD & XRechnung Validator directly in your browser. It checks all EN 16931 required fields and shows missing or incorrect fields.
In what format must the invoice date be specified?
The invoice date (BT-2) must be in YYYYMMDD format, e.g., 20260603. TaxLayer automatically sets this format correctly.
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