ZUGFeRD BT Fields: Business Terms for Practical E-Invoicing
Official references
Use these sources to verify dates, formats, and official rule changes.
Related Technical Wiki
Explore deep-dive developer documentation and regulatory guidelines matching this article.
ZUGFeRD and Factur-X hybrid invoices: PDF/A-3 with embedded CII/XML, profile levels (MINIMUM to EXTENDED), validation, and when to choose ZUGFeRD vs pure XML for Germany and EU B2B.
DIN EN 16931-1 semantic model: mandatory and optional data, national CIUS like XRechnung, how EN 16931 maps to UBL and CII, and what validators check before you send.
Understand when a hybrid ZUGFeRD or Factur-X PDF can be accepted as an archive-ready PDF/A-3 file.
Understanding ZUGFeRD BT Fields in Practice
ZUGFeRD invoices use EN 16931 Business Terms, usually shortened to BT fields. These fields define the invoice data that software validates and exchanges: invoice number, seller, buyer, totals, VAT treatment, payment details, and line information.
At Invoice-Converter.com, we map BT fields when converting between PDF, XRechnung, and ZUGFeRD. The resulting document still needs validation, especially when the source PDF is incomplete or ambiguous.
Quick Reference
- BT = Business Terms (standardized data elements)
- EN 16931 = European e-invoicing standard
- Business Terms defined in the EN 16931 semantic model
- Mandatory vs. Optional fields for compliance
What Are BT Fields?
BT fields (Business Terms) are standardized data elements defined by European standard EN 16931. Each BT field has a unique identifier (e.g., BT-1, BT-2) and represents specific invoice information such as invoice number, date, supplier details, or tax amounts.
ZUGFeRD Profile Availability Matrix
ZUGFeRD / Factur-X defines several profiles depending on the required level of business data detail:
| Profile | Target Use Case | Line Items Allowed? | EN 16931 Compliant? |
|---|---|---|---|
| MINIMUM | Essential buyer, seller, tax, and total information | No invoice line items | No (Header & Total only) |
| BASIC WL | Basic without lines (Header + Totals + Tax breakdown) | No | No |
| BASIC | Simple commercial invoices with a reduced data set | Yes (Simplified) | Partial |
| EN 16931 (COMFORT) | Core European B2B & B2G e-invoicing standard | Yes (Full BT set) | Implements EN 16931-1 |
| EXTENDED | Additional data beyond the EN 16931 core model | Yes (Advanced) | Conformant extension of EN 16931 |
Essential BT Fields Every Business Should Know
Core Invoice Information
- BT-1: Invoice number - Unique identifier for the invoice
- BT-2: Invoice issue date - Date when the invoice was created
- BT-3: Invoice type code - Type of invoice (380 = Commercial invoice, 381 = Credit note)
- BT-5: Invoice currency code - Currency of the invoice (e.g., EUR, USD)
- BT-6: VAT accounting currency code - Currency for VAT calculations
Supplier Information (Seller)
- BT-27: Seller name - Legal name of the supplier
- BT-28: Seller trading name - Commercial name if different
- BT-29: Seller legal registration identifier - Identifier from an official business register, where applicable
- BT-31: Seller VAT identifier - VAT registration number
- BT-32: Seller tax registration ID - Tax ID if no VAT number
Buyer Information
- BT-44: Buyer name - Legal name of the buyer
- BT-45: Buyer trading name - Commercial name if different
- BT-46: Buyer identifier - Identifier assigned to the buyer, such as an electronic address identifier
- BT-48: Buyer VAT identifier - VAT registration number
- BT-10: Buyer reference - Reference assigned by the buyer for routing or processing (a purchase order is BT-13)
Payment Information
- BT-9: Payment due date - Date when payment is due
- BT-81: Payment means type code - How payment should be made
- BT-83: Remittance information - Payment reference
- BT-84: Payment account identifier - IBAN or account number
- BT-86: Payment service provider identifier - BIC or bank code
BT Field Mapping Between Formats
When converting between different e-invoice formats, BT fields serve as the common language:
| BT Field | XRechnung (UBL) | ZUGFeRD (CII) |
|---|---|---|
| BT-1 | cbc:ID | rsm:ExchangedDocument/ram:ID |
| BT-2 | cbc:IssueDate | ram:IssueDateTime |
| BT-27 | cac:PartyName/cbc:Name | ram:Name |
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