What is PDF/A?
PDF/A is an archival standard based on ISO standard 19005, developed for the long-term preservation of documents. The A stands for archiving. While a regular PDF is designed for current display, PDF/A is intended to ensure a document looks exactly the same in 10, 20 or 50 years, regardless of what software is available at that point.
This sounds obvious but is not. Regular PDFs can embed external resources, use proprietary fonts or rely on encryption, all things that can become problematic for long-term archiving.
What makes PDF/A different
PDF/A establishes a set of restrictions that guarantee the document's self-sufficiency.
All resources embedded
Fonts must be fully embedded in the document. No external font files, no links to web fonts. This ensures the document looks identical everywhere.
No encryption
PDF/A files must not be encrypted. Content must be accessible without a password, as archiving locked documents makes no sense.
No JavaScript or embedded actions
Interactive elements such as JavaScript forms, auto-starting media content or embedded executable files are not permitted. The document must be static and safe.
Standardised colour management
All colours used must be defined by embedded ICC profiles to ensure colour fidelity over the long term.
Metadata in XMP format
PDF/A requires standardised metadata in XMP format that is machine-readable and facilitates archiving.
The different PDF/A variants
There are several PDF/A versions and conformance levels.
PDF/A-1 (ISO 19005-1, 2005)
The first and most strict variant, based on PDF 1.4. Widely used in public administration. Divided into PDF/A-1a (accessible, with document structure) and PDF/A-1b (visual representation only).
PDF/A-2 (ISO 19005-2, 2011)
Based on PDF 1.7, allows JPEG 2000 compression and embedded files. PDF/A-2 also supports PDF/A-1 conformant embedded files.
PDF/A-3 (ISO 19005-3, 2012)
Like PDF/A-2 but allows embedding of any file type, not just PDF/A. Used for electronic invoices in ZUGFeRD format where structured invoice data is embedded as XML.
When is PDF/A mandatory?
PDF/A is legally required or strongly recommended in various sectors:
- Government agencies and public administrations for electronic record-keeping
- Legal documents that must be retained long-term
- Electronic invoices in the public sector (ZUGFeRD uses PDF/A-3)
- Notaries and lawyers for digital archiving of deeds
- Companies subject to statutory retention obligations
Convert a PDF to PDF/A
Existing PDFs can be converted to the archival format using the PDF/A conversion tool at pdfmonster.de. The tool checks the document and adjusts it to meet PDF/A requirements, for example by embedding missing fonts.
If you want to compress a document before archiving it, use the compression tool first and then convert to PDF/A.
Conclusion
PDF/A is the standard for all documents that need to be archived permanently and reliably. Anyone facing regulatory requirements or simply wanting to ensure their documents remain usable long-term is well served by PDF/A. Conversion is simple and takes only a few seconds.