ZUGFeRD BT Fields: Business Terms for Practical E-Invoicing

Article overview

This article explains ZUGFeRD BT Fields: Business Terms for Practical E-Invoicing as a practical reference for European e-invoicing. It defines the topic in plain language, places it in the compliance context, and connects the explanation to invoice formats such as XRechnung, ZUGFeRD/Factur-X, UBL, and CII.

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.

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:

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

How to use this guide

Use the article as a starting point before changing a finance or ERP workflow: identify the applicable country rule or standard, decide which structured format is expected, validate the generated XML, and keep a documented exception process for invoices that require manual review.