ZUGFeRD BT Fields: Complete Guide to Business Terms in E-Invoicing

Understanding ZUGFeRD BT Fields: Your Complete Guide to Business Terms

When working with ZUGFeRD invoices, understanding BT (Business Terms) fields is crucial for creating compliant electronic invoices. These standardized fields ensure consistent data exchange between different systems and comply with the European standard EN 16931. This comprehensive guide will help you master BT fields for successful e-invoicing implementation.

At Invoice-Converter.com, we handle BT field mapping automatically when converting between PDF, XRechnung, and ZUGFeRD formats, ensuring your invoices always meet compliance requirements.

What Are BT Fields?

BT fields (Business Terms) are standardized data elements defined by the 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. These fields ensure that electronic invoices can be processed automatically across different systems and countries.

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 identifier - Company registration number
• 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 - Company registration number
• BT-48: Buyer VAT identifier - VAT registration number
• BT-10: Buyer reference - Purchase order or reference number

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 Fields for Tax Calculations

BT Field	Description	Example
BT-106	Sum of Invoice line net amount	1000.00
BT-110	Invoice total VAT amount	190.00
BT-112	Invoice total amount with VAT	1190.00
BT-115	Amount due for payment	1190.00

Line Item BT Fields

Each invoice line has its own set of BT fields for detailed product or service information:

• BT-126: Invoice line identifier - Unique line number
• BT-129: Invoiced quantity - Number of units
• BT-130: Invoiced quantity unit of measure - Unit code (e.g., C62 for pieces)
• BT-131: Invoice line net amount - Total excluding VAT
• BT-146: Item net price - Price per unit
• BT-151: Item VAT category code - VAT rate category

Mandatory vs. Optional BT Fields

Common BT Field Validation Rules

1. Format validation: Dates must be in YYYY-MM-DD format
2. Code list validation: Currency codes must be valid ISO 4217 codes
3. Calculation validation: Total amounts must match sum of line items
4. Conditional rules: If VAT exempt, exemption reason must be provided
5. Cross-field validation: Payment due date must be after invoice date

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

Best Practices for BT Field Implementation

1. Use standardized code lists: Always use official code values for countries, currencies, and units
2. Validate early and often: Check BT field compliance before sending invoices
3. Maintain data quality: Ensure accurate and complete information in all fields
4. Document custom extensions: If using additional fields, document them clearly
5. Test with trading partners: Verify that your BT field usage matches partner expectations

Common BT Field Errors and Solutions

BT Fields and German Compliance

For German e-invoicing compliance, additional considerations apply:

• Leitweg-ID (BT-10): Required for all B2G invoices in Germany
• German tax number formats: Must follow specific patterns for BT-32
• Payment terms: Skonto (cash discount) must be clearly specified
• Reverse charge indicators: Special coding for VAT-exempt B2B services

Automated BT Field Processing

Modern e-invoicing systems like Invoice-Converter.com handle BT fields automatically:

• Extract data from PDF invoices and map to correct BT fields
• Validate all mandatory fields are present and correctly formatted
• Calculate dependent fields (totals, VAT amounts) automatically
• Convert between different XML syntaxes while preserving BT field data
• Generate human-readable PDFs from BT field data

Future of BT Fields

The BT field standard continues to evolve with e-invoicing requirements:

• New fields for sustainability: Carbon footprint and environmental data
• Enhanced payment information: Support for instant payments and cryptocurrencies
• Supply chain integration: Links to logistics and inventory systems
• Real-time reporting: Fields for immediate tax authority submission