Ask most Austrian finance managers what format their e-invoices need to be in from 2026 and you’ll get a blank stare — or a vague answer about “XML” that doesn’t really capture the specifics. That’s understandable. The technical format question sits at an awkward intersection between IT, finance, and legal compliance. But it matters enormously in practice, because getting the format wrong means your invoices fail validation and never reach your customers at all.
This guide explains — in plain language — the three formats that matter for Austria e-invoicing: ebInterface, UBL 2.1, and Peppol BIS Billing 3.0. You’ll understand what each one is, when it applies, and what your business actually needs to implement before January 2026.
Why Format Matters So Much for Austria e-Invoicing
Electronic invoicing isn’t new in Austria — the country has required structured e-invoices for B2G (business-to-government) transactions for years. But the formats, delivery channels, and validation rules for B2G versus B2B invoicing differ significantly. Many Austrian businesses assume their existing B2G setup automatically covers their new B2B obligations. It often doesn’t.
The core requirement for B2B invoicing from 2026 is that invoices must be in a structured, machine-readable XML format transmitted through the Peppol network. Not a PDF. Not a PDF with embedded data. Not an HTML page. Structured XML — the kind that your customer’s ERP system can ingest and process automatically without a human reading and re-entering the data.
ebInterface: Austria’s National XML Standard
ebInterface is Austria’s home-grown structured invoicing format — developed by the Austrian Federal Economic Chamber (WKO) and widely used for B2G invoicing via the government’s Unternehmensserviceportal (USP). If you’ve been invoicing Austrian public sector entities, you’ve probably already encountered ebInterface, even if you didn’t know it by name.
The current version (ebInterface 6.1) supports the full range of invoice types — standard invoices, credit notes, advance payment requests — and is well-supported by Austrian accounting software vendors. Key characteristics include:
- XML-based, with a schema defined and maintained by WKO Austria
- Mandatory fields include supplier and buyer UID numbers, invoice number, date, line items with VAT breakdown, payment terms
- Supports Austrian-specific tax scenarios and VAT codes
- Widely supported in Austrian ERP and accounting systems
- Primarily used for B2G delivery via USP — not the primary format for Peppol B2B transmission
For B2B e-invoicing from 2026, ebInterface alone is not sufficient — you need to transmit via Peppol, which uses a different format standard. However, some Austrian access point providers offer ebInterface-to-UBL conversion, so your existing ebInterface setup might serve as a starting point rather than something to replace entirely.
UBL 2.1: The Foundation of Pan-European e-Invoicing
UBL — Universal Business Language — is an international XML standard maintained by OASIS that defines a library of business document formats. UBL 2.1 is the version used as the foundation for European structured invoicing. When people talk about “Peppol invoices,” they’re almost always talking about invoices structured according to the UBL 2.1 schema.
UBL 2.1 itself is a broad standard — it defines hundreds of possible fields across dozens of business document types. For e-invoicing specifically, the relevant UBL document types are Invoice and CreditNote. But UBL 2.1 on its own is like a language with a massive vocabulary and no grammar rules — you need a profile that specifies exactly which fields are mandatory, what code lists to use, and how the data should be structured for a specific market and use case. That’s where Peppol BIS 3.0 comes in.
Peppol BIS Billing 3.0: The Mandatory Standard for Austria B2B
Peppol BIS Billing 3.0 (Business Interoperability Specification) is the specific invoice format profile required for B2B e-invoicing through the Peppol network in Austria. Think of it as UBL 2.1 with strict rules applied — it specifies exactly which UBL fields are mandatory for Peppol, what values are allowed, and how the invoice data must be organised.
Key requirements of Peppol BIS 3.0 for Austria invoices include:
- Supplier and buyer identifiers: Both must be identified using their VAT/UID numbers in the correct format (AT:VAT scheme for Austrian entities)
- Mandatory invoice elements: Invoice ID, issue date, document currency code, tax subtotals per VAT rate, monetary totals, and at least one invoice line
- Peppol-specific code lists: VAT category codes (S, Z, E, AE, etc.), unit of measure codes from UN/ECE Rec 20, payment means codes from UNCL4461
- Electronic address scheme: Both sender and receiver must have valid Peppol electronic addresses (endpoint IDs) registered in the Peppol directory
- Schema validation: Invoices must pass both the UBL 2.1 XML schema validation AND the Peppol BIS 3.0 business rule validation (Schematron rules)
ERP platforms with native Peppol BIS 3.0 support for Austria include SAP S/4HANA (via SAP Document and Reporting Compliance), Oracle NetSuite (via the e-invoicing SuiteApp), and Oracle Fusion Cloud. Others like Oracle E-Business Suite and SAP ECC typically require middleware or Advintek connectors for Peppol BIS 3.0 output.
The CII Format: An Alternative to UBL
Alongside UBL 2.1, the Peppol network also accepts invoices in CII (Cross Industry Invoice) format — the UN/CEFACT Cross-Industry Invoice XML schema. CII is more commonly used in some EU markets and in the Factur-X/ZUGFeRD hybrid format (a PDF with embedded CII XML). For Austria specifically, UBL 2.1 is the more commonly implemented option, but if your ERP generates CII natively, it is technically valid on the Peppol network.
Format Validation: How to Know Your Invoices Are Correct
Before going live on the Peppol network, every Austrian business should validate their invoice output against the Peppol BIS 3.0 specification. Free validation tools are available:
- OpenPeppol’s online validator: Accepts your UBL XML file and checks it against both the UBL schema and the Peppol BIS 3.0 Schematron rules, returning a detailed pass/fail report.
- Your access point provider’s sandbox: Most certified access points provide a test environment where you can submit invoices and receive validation results before going live.
- ERP-level pre-validation: Some ERP platforms like Oracle NetSuite or Oracle Fusion Cloud validate invoice data against the Peppol schema before transmission.
Don’t skip validation. The most common implementation failures involve invoices that look correct in the ERP but fail Schematron business rule validation — often because of incorrect VAT category codes, missing mandatory elements, or mis-formatted identifier values.
How Advintek Handles Austria Format Complexity
Getting your ERP to output correctly structured Peppol BIS 3.0 invoices requires careful data mapping — ensuring that your internal invoice data translates correctly to the right XML elements, with the right code values, in the right structure. This is the part that takes the most time in any e-invoicing implementation and where errors are most common.
At Advintek Global Austria, our connectors come with pre-built Austria-specific data mappings for all major ERP platforms, reducing the mapping work from months to weeks and dramatically cutting the error rate during validation testing. We also support both ebInterface and Peppol BIS 3.0 from the same integration layer, which is important for businesses that need to maintain B2G compliance alongside their new B2B obligations.
For the broader compliance picture, see our Austria e-invoicing compliance guide and our overview of Peppol e-invoicing Austria compliance. For how similar format challenges were handled in other markets, the Oman e-invoicing ERP integration guide provides useful context on structured XML implementation across different regulatory environments.
Ready to get your invoice format right before the deadline? Contact Advintek Global Austria for a format assessment — we’ll review your current ERP output and tell you exactly what needs to change for full Peppol BIS 3.0 compliance.
