What's forbidden in PDF/A (and why)
- 🔒 No encryption — a password-locked file could become unopenable
- 🔤 No external font references — all fonts must be embedded
- 🎬 No audio/video or JavaScript — future readers might not support them
- 🔗 No external links as content dependencies — the file must stand alone
- 🎨 Device-independent color — colors defined so they reproduce faithfully anywhere
PDF/A-1, A-2, A-3 — and the a/b/u grades
| Version | Based on | Key addition |
|---|---|---|
| PDF/A-1 | PDF 1.4 | The original archival baseline |
| PDF/A-2 | PDF 1.7 | More features; allows PDF/A attachments |
| PDF/A-3 | PDF 1.7 | Can embed any file type (e.g. the source Word doc, XML invoice data) |
Each version comes in conformance grades: b (basic visual preservation), u (b plus full Unicode text mapping, so text extracts correctly), and a (u plus tagged, accessible document structure).
Why EU governments demand it
Public records must stay readable and legally trustworthy for decades — court filings, land registries, tax archives. Across the EU, administrations widely require PDF/A for official submissions and e-archiving, and PDF/A-3 is the backbone of structured e-invoicing formats that carry both a human-readable PDF and machine-readable XML in one file.
❓ PDF/A FAQs
What is PDF/A?
An ISO-standardized (ISO 19005) subset of PDF for archiving. Everything needed to display it — fonts, colors, metadata — is embedded in the file.
PDF vs PDF/A — what's the difference?
Regular PDFs may use external fonts, encryption or video. PDF/A forbids all of that so the file renders identically decades later.
What are PDF/A-1, A-2 and A-3?
Successive generations: A-1 (PDF 1.4 baseline), A-2 (PDF 1.7, more features), A-3 (can embed any file type, e.g. XML invoices).
Why do governments require PDF/A?
Official records must remain readable for decades. EU administrations widely mandate it for archiving and e-invoicing.
Related: What Is OCR? · What Is JSON? · Free Word to PDF