PDF/A – The format of the future – Part 3: PDF/A-3

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The third part of our PDF/A series covers PDF/A-3, which is considered the current standard for archiving and e-invoices. This does not mean that PDF/A-1 or PDF/A-2 are no longer valid. Depending on the use case, older PDF/A formats can still be fully sufficient. PDF viewers are backward-compatible, so PDF/A-1 remains valid even though newer formats exist. Still, PDF/A-3 is currently treated as the standard format.

Archive documents faithfully and compliantly with PDF/A​

Today, most larger organizations use a document management system (for example IBM Notes or SAP). These systems organize emails, process documents, and support workflows. At the same time, emails, attachments, and documents must be stored long-term. Data should be transferred into a reliable digital long-term archive, and everything in that archive must remain searchable and accessible regardless of elapsed time or future technical conditions. If all data is stored in such an archive (audit-proof and accessible), legal requirements are met and workflows can be accelerated.

What distinguishes PDF/A-3 from PDF/A-1 and PDF/A-2?​

The PDF/A family has been extended over time, and PDF/A-3 is an extension of PDF/A-2. With PDF/A-3, arbitrary file types can be embedded, which significantly simplifies document handling. Original data formats such as XML or CAD can be attached directly. In addition to features already available in earlier versions, PDF/A-3 remains suitable as a secure long-term archive format while also allowing source formats to be preserved.

PDF/A-3: Store original files in addition to the PDF/A file​

The third part of the PDF/A standard, ISO 19005-3, was published in 2012. It allows not only PDF/A-compliant attachments but all file types to be embedded. Attachments can be associated with a full document, part of a document, or a specific page.

To archive two objects while accessing only one digital object, container functionality was introduced. This container can include original source data plus an additional PDF/A document for long-term preservation. A typical example is storing a signed XML file together with a long-term archived PDF/A document.

This container approach is also useful for email archiving: emails and attachments can be converted to PDF/A and transferred together into long-term storage. With PDF/A-3, original attachment formats (for example OpenOffice or Microsoft Office files such as text documents and spreadsheets) can remain embedded in the archived email.

E-invoices with PDF/A-3​

PDF/A-3 introduced container support and therefore expanded options for e-invoicing. It allows machine-readable XML data to be embedded while also storing an archive-ready PDF invoice. Since June 2014, the ZUGFeRD standard has been available on top of PDF/A-3. This makes it possible to create PDF invoices that are well suited for long-term archiving.

In addition to PDF/A, several specialized PDF subformats have emerged depending on use case. We cover these in the next posts of this series:

  • PDF/X and PDF/VT: printing industry
  • PDF/UA: Accessible PDFs
  • PDF/E: technical documents
  • PDF/H: healthcare sector
  • PDF/A compared with TIFF