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What Is PDF/A? A Guide to the Long-Term Archiving Standard

Businesses and government agencies increasingly need to preserve digital documents for extended periods. However, standard PDFs may not display correctly in the future due to external font references, broken links, or missing resources.

This is where PDF/A comes in. In this article, we'll explain what PDF/A is, its different types, and when you should use it.

What Is PDF/A?

PDF/A is a PDF standard designed for long-term preservation (archiving) of electronic documents, standardized as ISO 19005. The "A" stands for "Archive."

The key difference from regular PDFs is that PDF/A files are "self-contained." All information needed to display the document — fonts, color profiles, metadata — is embedded within the file. With no external dependencies, the document is guaranteed to look the same 10 or 50 years from now.

Types of PDF/A

PDF/A comes in several levels, each with different strictness requirements.

  • PDF/A-1 (ISO 19005-1): The first version, based on PDF 1.4. Has strict constraints including mandatory font embedding, no encryption, and no JavaScript
  • PDF/A-2 (ISO 19005-2): Based on PDF 1.7. Adds JPEG2000 compression, PDF/A file attachments, and transparency support
  • PDF/A-3 (ISO 19005-3): An extension of PDF/A-2 that allows non-PDF/A files (Excel, XML, etc.) to be attached. Widely used in electronic invoicing (ZUGFeRD/Factur-X)

When to Use PDF/A

PDF/A is particularly useful in the following scenarios.

  • Legal document archiving: Contracts, court records, and regulatory documents that must be stored for extended periods
  • Government document management: As administrative processes go digital, submission in PDF/A format is increasingly required
  • Medical record storage: Patient charts and test results that need accurate long-term preservation
  • Corporate document management: Accounting documents, meeting minutes, and internal policies that may need future reference

How to Create PDF/A Files

PDF/A files can be created in several ways.

  • Export from Office software: Microsoft Word and LibreOffice offer options to save in PDF/A format
  • Convert with PDF editors: Adobe Acrobat and Foxit PhantomPDF can convert existing PDFs to PDF/A
  • Online tools: Some online tools offer PDF/A conversion, but be cautious about uploading sensitive documents

Tips for Working with PDF/A

Keep these points in mind to effectively work with PDF/A.

  • Embed all fonts: External font references are not allowed, so all used fonts must be embedded in the file
  • No JavaScript or video: PDF/A prohibits executable content such as JavaScript and Flash video
  • Validate with verification tools: Use open-source tools like veraPDF to verify that your PDF/A files meet ISO requirements

Summary

PDF/A is an international standard for reliably preserving electronic documents into the future. When dealing with legally mandated documents or files requiring long-term storage, consider saving in PDF/A format instead of standard PDF. Understanding the different types and requirements will help you build a more effective archiving strategy.