# PDF/A-3 and ZUGFeRD archive readiness

ZUGFeRD combines a PDF/A-3 container with embedded CII XML. The XML can be valid while the source PDF still fails archive checks.

## What you may see

- The XML validates, but a receiver or external portal reports PDF/A-3 or archive-readiness errors.
- The app marks the original PDF as not strictly archive-ready.
- A PDF exported as PDF/X still fails a PDF/A-3 check.

## Why this matters

ZUGFeRD and Factur-X are hybrid files: the structured invoice is embedded in a PDF/A-3 document. PDF/X is a print standard and does not prove PDF/A-3 archive conformance.

## How to fix it

1. Export the source document as PDF/A-3b or PDF/A-3 from the authoring tool, for example InDesign or Acrobat.
2. Upload the PDF/A-3 source again and run review validation before downloading the hybrid file.
3. Validate both layers: the embedded XML and the PDF container.

## Before you retry

- Check that the source PDF was re-exported, not only renamed.
- Keep the archive-readiness note as information unless your recipient explicitly requires strict PDF/A-3 acceptance.
- If a portal reports image or font dictionary errors, fix the source PDF export settings first.

## Common question

### Is PDF/X enough for ZUGFeRD?
No. PDF/X is for print exchange. ZUGFeRD and Factur-X require a PDF/A-3-style hybrid container.