Free UBL 2.1 Invoice Validator

UBL (Universal Business Language) 2.1 is an OASIS open standard XML format for business documents. It's the foundation for Peppol BIS and many national e-invoicing implementations, supporting invoices, orders, and 60+ document types.

Check your e-invoice

or

Your file is used only to check and fix your invoice, and kept so you can re-download your result.

What We Check for UBL

UBL 2.1 XML schema validation
EN 16931 business rules
Namespace and element structure
Code list validation
Party and address structure
Tax calculation rules
Invoice line consistency

Countries Using UBL

🇪🇺European Union🇦🇺Australia🇳🇿New Zealand🇸🇬Singapore

Common UBL Errors

UBL-CR-001Invalid XML syntax
UBL-CR-002Invalid namespace
UBL-SR-01Namespace declaration required
UBL-SR-06Invalid date format
UBL-CR-005Empty element not allowed
Browse all error guides

Validator vs Access Point vs ERP Built-in

Invoice Navigator

Schema + business rules in one check. Identifies namespace issues, element structure problems, and EN 16931 violations.

Access Point

Peppol Access Points validate UBL but only for Peppol-specific rules. Generic UBL validation not included.

ERP Built-in

ERP systems generate UBL but rarely validate against full schema. Structural issues may only surface at recipient.

UBL Quick Facts

Full Name

Universal Business Language

Version

2.1

Maintained By

OASIS

Document Types

65+

Used By

Peppol, XRechnung

UBL FAQ

What is UBL 2.1?
UBL (Universal Business Language) 2.1 is an open XML standard for business documents developed by OASIS. It defines schemas for invoices, orders, and 60+ other document types.
Is UBL the same as Peppol?
No. UBL is the document format; Peppol is the network. Peppol BIS Billing is built on UBL 2.1 with additional business rules.
Should I use UBL or CII for EN 16931?
Both are valid syntaxes for EN 16931. UBL is more common internationally (Peppol uses it), while CII is used in hybrid formats like ZUGFeRD.
What are cbc: and cac: prefixes?
These are UBL namespace prefixes. cbc: (Common Basic Components) contains simple values, cac: (Common Aggregate Components) contains complex structures.
Which standards are built on UBL?
Peppol BIS Billing 3.0, XRechnung (UBL variant), A-NZ PEPPOL (Australia/New Zealand), and Singapore InvoiceNow all use UBL 2.1 as their base syntax. Our validator checks generic UBL compliance—use format-specific validators for additional business rules.

Related Formats

Peppol BISXRechnungEN 16931

Learn More About UBL

Understand the technical details, history, and best practices.

Read the guide

Related Content

Countries
E-Invoicing in GermanyE-Invoicing in France
Errors
Netherlands E-Invoice Errors
Answers
What is Peppol BIS Billing 3.0 and how does it work?How do you validate an e-invoice?
Regulations
EN 16931
Validators
XRechnung ValidatorZUGFeRD Validator

100% Private Validation

All validation runs entirely in your browser. Your invoice files never leave your device and are never sent to our servers. We can't see your data even if we wanted to.