Guides
Understand e-invoicing in ten minutes
Short, accurate guides to the standards and national mandates — written for finance teams and developers alike.
Basics
What is Peppol BIS Billing 3.0?
A practical introduction to Peppol BIS Billing 3.0: the network, the document format, identifiers and the rules that matter when you send invoices.
EN 16931 explained: the European e-invoice standard
What EN 16931 is, how business terms and business rules work, the two syntaxes UBL and CII, and how national profiles (CIUS) build on top of it.
UBL vs. CII: which e-invoice syntax should you use?
The two EN 16931 syntaxes compared: structure, tooling, Peppol, Factur-X/ZUGFeRD and XRechnung — and how to convert between them.
ViDA: what VAT in the Digital Age means for e-invoicing
The EU's VAT in the Digital Age package: member state freedom since 2025, mandatory intra-EU e-invoicing and digital reporting from 1 July 2030.
Country guides
Germany's e-invoicing obligation: 2025, 2027 and 2028
Who must receive and send e-invoices in Germany and when, which formats are accepted (XRechnung, ZUGFeRD, Peppol) and what the transition rules mean.
France's e-invoicing reform: September 2026 and 2027
The French B2B e-invoicing and e-reporting reform explained: dates, company sizes, plateformes agréées and the Factur-X, UBL and CII formats.
Belgium's 2026 Peppol mandate: what changed
Belgian B2B e-invoicing has been mandatory since 1 January 2026. Who is covered, why Peppol is the default, identifiers, and what to expect for 2028 e-reporting.
How-to
How to fix the 10 most common e-invoice validation errors
BR-CO-15, BR-CO-17, BR-S-08, PEPPOL-R003 and more: what the most frequent EN 16931 and Peppol errors mean and how to fix them in your ERP.
Reverse charge on e-invoices: getting category AE right
How to issue an EN 16931 compliant reverse-charge invoice: VAT category AE, exemption reason VATEX-EU-AE, both VAT numbers and zero rates.