# ZUGFeRD BT Fields: Complete Guide to Business Terms in E-Invoicing - Date: 2025-01-18 - Reading time: 10 min read Master ZUGFeRD BT fields for compliant e-invoicing. Learn about business terms, field mappings, validation rules, and implementation best practices for German and EU electronic invoicing standards. ## Article overview This article explains ZUGFeRD BT Fields: Complete Guide to Business Terms in 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. 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. ## 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. ### 📋 Quick Reference - **BT** = Business Terms (standardized data elements) - **EN 16931** = European e-invoicing standard - **400+ BT fields** defined in the standard - **Mandatory vs. Optional** fields for compliance ### 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 #### ⚠️ Compliance Requirements **Mandatory fields** must always be present for a valid invoice: - Invoice number (BT-1) - Invoice issue date (BT-2) - Invoice type code (BT-3) - Invoice currency code (BT-5) - Seller name (BT-27) - Buyer name (BT-44) - Invoice line net amount (BT-131) - Invoice total amounts (BT-106, BT-110, BT-112) **Optional fields** provide additional information when needed: - Purchase order reference (BT-13) - Contract reference (BT-12) - Project reference (BT-11) - Delivery date (BT-72) ### Common BT Field Validation Rules - **Format validation:** Dates must be in YYYY-MM-DD format - **Code list validation:** Currency codes must be valid ISO 4217 codes - **Calculation validation:** Total amounts must match sum of line items - **Conditional rules:** If VAT exempt, exemption reason must be provided - **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 - **Use standardized code lists:** Always use official code values for countries, currencies, and units - **Validate early and often:** Check BT field compliance before sending invoices - **Maintain data quality:** Ensure accurate and complete information in all fields - **Document custom extensions:** If using additional fields, document them clearly - **Test with trading partners:** Verify that your BT field usage matches partner expectations ### Common BT Field Errors and Solutions #### ❌ Frequent Mistakes - **Missing mandatory fields:** Always check that all required BT fields are populated - **Invalid date formats:** Use ISO 8601 format (YYYY-MM-DD) consistently - **Incorrect VAT calculations:** Ensure BT-110 equals sum of all VAT amounts - **Wrong currency codes:** Use three-letter ISO codes (EUR, not €) - **Mismatched totals:** Line item sum must equal invoice subtotal ### 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 #### Ready to Master BT Fields? Let Invoice-Converter.com handle the complexity of BT field mapping and validation for you. Our advanced conversion engine ensures: - Automatic extraction and mapping of all BT fields - Validation against EN 16931 and German requirements - Seamless conversion between formats - Clear error messages for missing or invalid fields ## 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.