What Does PDF/UA Require?
PDF/UA establishes a set of technical requirements that a PDF must satisfy to be considered universally accessible. These requirements ensure that the document's content, structure, and metadata are interpretable by assistive technologies.
Complete Tag Structure
Every piece of content must be tagged with its semantic role — headings, paragraphs, lists, tables, figures, and form fields. Decorative elements must be explicitly marked as artefacts so assistive technologies ignore them. No content may exist outside the tag structure.
Logical Reading Order
The tag structure must define a reading sequence that reflects the logical order of the content, not the visual layout. This is critical for multi-column layouts, sidebars, and documents where the visual arrangement does not match the intended reading flow.
Alternative Text for Non-Text Content
All images, charts, and other non-text elements must have alternative text that conveys the equivalent information. This text must be meaningful and contextually appropriate — not simply a file name or generic description.
Table Structure
Tables must be properly tagged with header cells, data cells, and scope attributes. Complex tables with spanning cells or multiple header levels require additional structure to ensure assistive technologies can associate data with the correct headers.
Document Metadata
The document must declare its language, have a meaningful title (not a file name), and include bookmarks for navigation in longer documents. Font information must be embedded to ensure correct rendering across platforms.
PDF/UA-1 vs PDF/UA-2
Two versions of the standard exist, each based on a different version of the PDF specification.
PDF/UA-1 (ISO 14289-1)
Published in 2012 and based on PDF 1.7. This is the version most commonly referenced by current regulations and compliance frameworks. It defines the foundational requirements for accessible PDF structure.
Most current compliance obligations reference this version.
PDF/UA-2 (ISO 14289-2)
Published in 2024 and based on PDF 2.0. Introduces enhanced support for mathematical content via MathML, improved annotation handling, better structure for complex layouts, and expanded metadata capabilities.
Adoption is growing but PDF/UA-1 remains the baseline.
How PDF/UA Relates to WCAG
PDF/UA and WCAG are complementary standards. WCAG provides broad accessibility guidelines for all digital content, while PDF/UA defines the specific technical implementation for PDF documents.
In practice, a document that meets PDF/UA requirements will satisfy most of the PDF-related success criteria in WCAG 2.1 AA. The European Accessibility Act references EN 301 549, which in turn points to both WCAG and PDF/UA. Most regulatory frameworks treat PDF/UA as the technical benchmark for accessible PDF production.
Understanding both standards matters because WCAG defines the outcomes required (perceivable, operable, understandable, robust) while PDF/UA defines the technical implementation that delivers those outcomes in a PDF context.
How ComplyLoft Validates Against PDF/UA
ComplyLoft auto-tags document structure, repairs reading order, and validates outputs against PDF/UA requirements. The platform identifies missing tags, incorrect nesting, absent alternative text, and structural issues that would cause PDF/UA validation to fail.
For high-volume documents with consistent templates, this validation can be applied at scale across thousands of files. For complex documents, ComplyLoft flags the issues that need human attention so specialists can focus their time on the decisions that require expertise.
ComplyLoft automates the groundwork. A qualified human always reviews, adjusts where needed, and signs off on all outputs.
Explore the Accessibility ToolRelated Accessibility Resources
What is PDF Accessibility?
A complete introduction to PDF accessibility — what it means, who it affects, and the legal landscape.
WCAG PDF Compliance Explained
How WCAG applies specifically to PDF documents, common failures, and testing methods.