Archive Compliance: How to Store e-Invoices for 10–30 Years
Key Takeaways
- In many EU countries, you need to keep e-invoices for at least 8 years. Some types of transactions require you to store them for up to 30 years.
- You must keep archived e-invoices readable, authentic, and unchanged for the whole retention period.
- To archive e-invoices properly, you need the right technical setup and clear, documented compliance processes.
- Using cloud-based archiving makes it easier to comply with rules in different countries and helps reduce long-term storage costs.
- Being ready for an audit is about how quickly you can find and provide the correct e-invoice in the required format.
Tax authorities won't wait for you to organize your archive. When you receive an audit request, you must provide e-invoices from past years that are readable, authentic, and demonstrate clear integrity. Retention periods are often longer than many finance teams realize.
What “Long-Term” Actually Means for e-Invoice Storage
In many EU countries, the minimum retention period is eight years. In Mexico and some LATAM markets, you must retain CFDI e-invoices for a minimum of five years. Some transactions, such as those involving real property or long-term contracts, may require you to keep records longer. Always check local rules for your specific transactions.
The retention period usually starts at the end of the fiscal year in which the transaction occurred, not when you send the e-invoice. For example, if you issue an e-invoice in January 2024, you may need to keep it accessible until late 2031 or longer.
You must know the exact requirements for your country. This is the first step to compliant e-invoice archiving.
The Four Pillars of a Compliant e-Invoice Archive System
Regulators care how e-invoices are stored, not only whether you have them. In the EU and most other markets, compliant archiving depends on four main requirements:
- Authenticity means you must be able to prove the e-invoice really came from the issuer. This is usually done with qualified electronic signatures or EDI exchanges that provide a clear audit trail.
- Integrity means the e-invoice content hasn't changed since it was issued. Any tampering, even accidental, can render an archived e-invoice invalid for tax purposes.
- Legibility means the e-invoice must remain readable to people for the entire retention period. Your archive format should still work in 10 or 20 years, so avoid formats that depend on software that might not be available in the future.
- Accessibility is the fourth key point. You must be able to quickly retrieve archived e-invoices if a tax authority requests them.
Why Your ERP System Isn't Enough
Many businesses think their accounting software handles archiving. It doesn't, at least not in the way regulators expect.
ERP systems keep data for daily operations, but not always in a format that meets legal or tamper-proof standards. The format you use is more important than many think. PDF/A is commonly accepted for human-readable archiving. Structured formats like XML, used in Peppol, ZUGFeRD, Factur-X, and KSeF, are often required for machine-readable storage. In some countries, you must keep both formats together.
Cloud-based archiving platforms designed for e-invoice retention can automatically convert formats, validate signatures, and organize e-invoices for easy retrieval. They also make it much easier to comply with rules in several countries at once.
Country-Specific Rules You Can't Afford to Miss
Retention rules vary from country to country, and these differences matter.
In Germany, e-invoices must be stored for 8 years in an unaltered, machine-readable format, following a reduction in the retention period that took effect in July 2025. Germany's phased B2B e-invoicing mandate, fully in force for all businesses from January 1, 2028, makes it the smarter move to get your archiving setup right now. See the full German B2B e-invoicing timeline.
In France, e-Invoices must be archived for 10 years. The Factur-X hybrid format must retain both its PDF and embedded XML components. Stripping it down to a simpler format for storage convenience risks non-compliance.
In Italy, all e-Invoices pass through the SDI platform before reaching the recipient.
Both the issuing and receiving companies have independent archiving obligations, each required to preserve their own copy under the conservazione sostitutiva framework, which requires digital signatures, time stamps, and a documented Conservation Manual.
Poland's KSeF platform became mandatory in February 2026 for large taxpayers and in April 2026 for all other VAT-registered businesses, centralizing e-invoice storage at the national level. Archiving obligations for e-Invoices issued before those dates remain in force and run in parallel. For e-invoices issued through KSeF, the platform handles archiving on behalf of taxpayers, removing the need to maintain a separate archive for those documents.
How to Build an Archive That Survives an Audit
Being ready for an audit goes beyond storing e-invoices. You need to find a specific e-invoice, in the right format, with all details, within minutes if asked.
Your e-invoice archiving system should have a good indexing structure so that you can search by date, supplier, invoice number, or transaction type. It also needs access controls for retrieval, and you should be able to show and record how e-invoices are accessed.
Test your archive now. Choose a random e-invoice from five years ago and see if you can find it in less than five minutes. If you can't, you have a gap in your audit readiness that should be addressed before an authority notices it.
If you're moving into new markets or getting ready for a new e-invoicing rule, now is a good time to check your archiving setup.
Not sure if your current setup meets the requirements? Talk to the Comarch e-Invoicing team before the deadline arrives.
