GoBD & Process Documentation for E-Invoices: Archive the XML, Not the Printout

Archiving used to be the boring part of invoicing. E-invoicing changed that. Under GoBD, an e-invoice is only correctly archived if you keep the original structured XML — unaltered and audit-proof. A great many businesses instead save a nice-looking PDF or a printout, and that is not enough. This article sets out exactly what GoBD requires and how the Verfahrensdokumentation fits in.

> Short answer: Archive the original structured XML unaltered and audit-proof — a PDF or printout is insufficient (BMF letter of 15 October 2025). Retention is 8 years (BEG IV, from 1 January 2025). In hybrid ZUGFeRD the XML is authoritative. You also need a four-part Verfahrensdokumentation plus a documented internal control system.

The core rule: keep the XML

An e-invoice's legal substance is its structured XML. GoBD therefore requires you to retain that XML — the original file, unchanged — for the full retention period. The BMF letter of 15 October 2025 is explicit: a PDF or printout is not sufficient. You cannot render the invoice to PDF, file the PDF, and delete the XML; the machine-readable original is what the tax authority may want to inspect and re-validate.

This has a direct consequence for ZUGFeRD: in a hybrid file the XML is authoritative. The embedded PDF is a convenience view for humans. So even though the file *looks* like a PDF, the part you must preserve intact is the XML inside it. Archive the whole original file (which contains the XML) — do not extract only the visible PDF.

Retention is now 8 years, not 10

A welcome change: the retention period was shortened to 8 years by BEG IV, effective 1 January 2025. This flows through the three relevant provisions:

If your archiving policy still says "ten years" for invoices, update it. Over-retaining is less dangerous than under-retaining, but the correct figure is now 8.

What "audit-proof" actually means

"Audit-proof" (revisionssicher) is not just "saved somewhere." The archived file must be:

• Unalterable without trace — changes must be impossible or detectable
• Complete and legible — nothing missing, machine-readable throughout
• Retrievable — findable and readable for the whole 8-year period

Dropping the XML into a shared folder that any user can edit or overwrite does not meet this bar. You need storage that guarantees integrity over time — a proper archive system or accounting platform's archive, not an ordinary directory.

The Verfahrensdokumentation: four parts

GoBD also expects a Verfahrensdokumentation — documentation of how your invoice processes actually work. It has four parts:

1. General description — what the process is and which data it handles
2. User documentation — how people operate the process step by step
3. Technical system documentation — the systems, formats, and data flows involved
4. Operating documentation — how the systems are run, backed up, and controlled

On top of these four parts, you must have a documented internal control system (IKS): the checks that ensure invoices are captured completely and correctly (for example, validation before sending, authorisation steps, reconciliation).

For a small business this does not have to be a book — it can be a concise document — but it must genuinely describe *your* process. A generic template that does not match reality is worse than none, because it misrepresents your controls.

Common mistakes to avoid

• Archiving only the PDF and discarding the XML — the single most frequent GoBD failure with e-invoices.
• Editing the file to "clean it up" before archiving — the original must be unaltered.
• Storing in an editable folder — fails the audit-proof requirement.
• No Verfahrensdokumentation — leaves you unable to demonstrate your process during an audit.
• Assuming 10 years — the figure is now 8.

The supplier-PDF trap

There is a subtle archiving problem when a supplier sends a plain PDF rather than a real e-invoice. That PDF has no structured XML to archive — there is nothing authoritative to preserve, and it is not a valid e-invoice under § 14 UStG anyway. Converting it into a structured ZUGFeRD or XRechnung file gives you an actual e-invoice with an XML you can archive to GoBD standard.

Archive the right file from the start

GoBD compliance begins with keeping the correct original file: the structured XML, unaltered, for eight years, backed by a process you can describe.

TaxLayer produces structured ZUGFeRD and XRechnung files — and converts stray supplier PDFs into structured e-invoices — so the file you archive is the authoritative one GoBD expects. The first two conversions each month are free — no credit card required.