PDF/UA-2 explained: what ISO 14289-2 changes for PDF 2.0, and when you actually need it

PDF/UA-2 is the second part of the ISO standard for accessible PDF and the first written for PDF 2.0. It answers a question PDF/UA-1 could not, because PDF/UA-1 predates PDF 2.0 by five years: what does a fully accessible PDF 2.0 file look like? This guide explains what the standard contains, how it relates to PDF/UA-1 and to the free WTPDF specification it was built from, and what practical difference it makes to a team that has to produce or buy accessible documents in 2026.

Where PDF/UA-2 comes from

According to the PDF Association, PDF/UA-1 was introduced in 2012 and last revised in 2014, providing accessibility requirements based on ISO 32000-1, which is PDF 1.7. PDF 2.0 (ISO 32000-2) was released in 2017 and updated in 2020 with what the Association calls "numerous enhancements relevant to Tagged PDF". In February 2024 the Association published WTPDF, the Well-Tagged PDF specification, defining accessibility and reuse requirements for PDF 2.0. ISO 14289-2 elevated those same requirements to an International Standard; the Association announced its arrival on March 15, 2024, noting that ISO 14289-2 must be purchased while WTPDF is freely available. The normative text was developed by the Association's PDF/UA and PDF Reuse technical working groups together with ISO TC 171/SC 2/WG 9.

What it adds over PDF/UA-1

The PDF Association summarises the enhancements to core tagged PDF requirements as comprehensive requirements for structure element attributes, comprehensive requirements for the use of annotations, and examples of semantically significant attribute usage. Building on PDF 2.0 itself, PDF/UA-2 and WTPDF then add:

• comprehensive requirements for the new structure element types introduced in PDF 2.0;
• rules governing the inclusion of structure elements defined in PDF 1.7 as well as PDF 2.0;
• detailed requirements for math, including support for MathML;
• requirements for intra-document links using the structure destinations feature;
• use of the Associated Files feature to integrate non-PDF content.

The math provision is the one most people notice. PDF/UA-1 could only require that a formula be tagged and given alternative text; PDF/UA-2 provides for MathML, which is what screen readers and braille displays need to navigate an equation rather than hear a description of it. That is why the LaTeX Project's tagged PDF work targets PDF/UA-2 rather than PDF/UA-1; see accessible PDFs from LaTeX.

PDF/UA-1 is not withdrawn

Because the two parts are written against different PDF versions, PDF/UA-2 does not replace PDF/UA-1. A PDF 1.7 file claims PDF/UA-1; a PDF 2.0 file claims PDF/UA-2. The PDF Association notes that PDF/UA-1 has been broadly implemented in software and is referenced directly and implied in regulations around the world, which will remain true for years. A document produced as PDF 1.7 with a correct tag structure is not made less accessible by the existence of the newer standard.

What the law asks for

No major accessibility regulation names PDF/UA-2 as a requirement. The ADA Title II web rule requires WCAG 2.1 Level AA for web content including documents; the European standard EN 301 549 applies WCAG-derived requirements to non-web documents in its clause 10; the UK's public sector regulations point at WCAG 2.2 AA. PDF/UA in either part is a technical means to reach those outcomes and a strong form of evidence, particularly for procurement, but a PDF/UA identifier in a file is not compliance with any of them. The PDF/UA versus WCAG guide explains the relationship.

Tool support in 2026

Viewer and screen reader support for PDF 2.0 structure, and for MathML inside PDF in particular, is the weak link. A file can be valid PDF/UA-2 and still be read poorly by a viewer that only understands PDF 1.7 structure. Until that changes, test PDF/UA-2 output with the assistive technology your readers use, following how to test a PDF with a screen reader, and consider providing an HTML alternative for math-heavy content.

When to choose it

• Choose PDF/UA-2 when the producer already writes PDF 2.0, when equations must be navigable rather than described, or when a buyer names it.
• Stay on PDF/UA-1 when the toolchain and validators are built around PDF 1.7, which is still most of the remediation market, and when the content has no need of PDF 2.0 features.
• In both cases the human checks are the same: reading order, heading logic, table headers, alternative text quality, and a screen reader pass.

Frequently asked questions

Sources

The statements above rest on the primary sources below. Where a source is a law or standard, the version and date named in the text are the ones checked on the review date. This guide is general information, not legal advice.

1. PDF Association, March 15, 2024: ISO 14289-2 (PDF/UA-2), the gold standard for accessibility in PDF 2.0, has arrived . Publication, relationship to WTPDF and PDF/UA-1, and the list of enhancements quoted here.
2. PDF Association: ISO 14289-2 (PDF/UA-2) resource page
3. LaTeX Project: Using LaTeX to produce accessible PDF
4. WeasyPrint documentation: API reference
5. Prince documentation: PDF output and profiles
6. veraPDF validation profiles: PDF/UA Part 2 rules
7. eCFR: 28 CFR Part 35, Subpart H, Web and Mobile Accessibility . The Title II rule names WCAG 2.1 Level A and AA.