E-Invoicing with Odoo: Setting Up XRechnung and ZUGFeRD Correctly

By Noha Sarwat, Consultant at FlexCode Systems

Why XRechnung and ZUGFeRD are a priority now

Germany is rolling out EU Directive 2014/55/EU in stages: the obligation to be able to receive e-invoices took effect in January 2025, followed by the obligation to issue them in 2027 and 2028 for all B2B businesses.

§§ Jan. 2025 | receiving obligation active | Jan. 2027 | issuing obligation (large businesses) | 15-20 hrs | saved per month | EN 16931 | applicable EU standard

XRechnung vs. ZUGFeRD: what's the difference?

XRechnung - pure XML

• Format: Machine-readable only (no PDF)
• Use: Mandatory for invoices to public sector clients (B2G), increasingly B2B
• Strength: Fully automated processing - no manual data entry for the recipient

ZUGFeRD - the smart hybrid format

• Format: PDF with an embedded XML file
• Use: B2B and the transition period
• Strength: Dual compatible - human-readable for everyone, machine-readable for ERP systems

For B2B invoices, we recommend ZUGFeRD Profile EN 16931 - your supplier can read the PDF, and your system processes the XML automatically.

Step by step: activating ZUGFeRD in Odoo

Step 1: Activate the module

Settings → General Settings → Accounting → enable ZUGFeRD, select Profile EN 16931.

Step 2: Check your company master data

Complete address, VAT ID (format: DE123456789), IBAN.

!! Incomplete master data is the most common cause of validation errors in ZUGFeRD export.

Step 3: Create and validate your first invoice

Create a test outgoing invoice → Send and Print → ZUGFeRD PDF. Upload the file to validator.mustangproject.org.

Processing incoming invoices automatically

The biggest efficiency gain lies in automatic receiving:

1. Set up an email alias - e.g. invoice@yourcompany.com
2. Automatic recognition - Odoo reads out all invoice data
3. Posting proposal - pre-filled fields: supplier, amount, tax, due date
4. Review and approval - the accountant reviews and posts with one click

✓ At 100 incoming invoices a month, this realistically saves 15-20 hours of manual entry.

The legal timeline in detail

The e-invoicing obligation is being phased in, depending on company size and role:

!! The receiving obligation already applies now to every business - regardless of revenue or size. If you can't yet process ZUGFeRD PDFs, that should be a priority.

Archiving: what applies for the retention requirement

E-invoices are subject to the same retention rules as traditional documents - with one important addition:

• 10-year retention requirement, as with all accounting vouchers
• Archive the original format - the XML file (with ZUGFeRD: the embedded XML), not just a printout or screenshot
• Ensure immutability - Odoo automatically archives incoming and outgoing e-invoices in their original format with a timestamp

✓ If you already process e-invoices through Odoo, you meet this requirement automatically - with no additional archiving system.

Quick FAQ

Do I have to issue e-invoices already as a small business?

No, the obligation to issue them is phased in only from 2027 (larger businesses) and 2028 (everyone). However, you have had to be able to receive e-invoices since January 2025.

Isn't a normal PDF invoice by email enough anymore?

Not for B2G invoices (to public authorities). For B2B, a simple PDF is usually still accepted during the transition, but it becomes the exception as the 2027/2028 deadlines approach.

What if my supplier doesn't send e-invoices yet?

As long as the issuing obligation doesn't yet apply to that sender, this is permitted. Odoo keeps processing traditional PDFs in parallel.

Conclusion

FlexCode Systems configures e-invoicing formats as standard on every Odoo implementation. Talk to us - we'll get your system e-invoice-ready in half a project day.