Do not publish PDF-only or Word-only content on the website. PDFs and Word documents are difficult to use with assistive technology and are unlikely to meet the accessibility standards required by law.

Research and Government Digital Service (GDS) guidance shows that users find PDFs more difficult to use than web pages. PDF files are less accessible than HTML pages, so should not be used without an HTML alternative.

If a PDF or Word file is necessary and it is not possible to provide an HTML alternative of the content, such as when publishing guidance for older surveys, make sure the documents are altered to meet accessibility standards.

Failing to make PDFs accessible could break the Equality Act 2010.

The PDF should have:

• correctly tagged headings, text, bullet lists, tables and images so screen readers can understand the structure
• a logical reading order for users navigating the document using the tab key on a keyboard
• alternative (alt) text added to all images
• bookmarks for all main headings in the navigation pane and the PDF file set to open this pane automatically
• all content written in plain English following ONS house style conventions
• a hierarchy of headings created using styles: “heading 1”, “heading 2” and so on (do not use bold, italics or all capitals)
• all text in a sans serif font like Arial or Helvetica, with a minimum size of 12 points, left-aligned, and in single columns

If you are creating a PDF using Microsoft Word or PowerPoint, you can use the built-in accessibility checker to pick up issues that are affecting your document before you export it to PDF.

After creating your PDF, you should also use the accessibility checker in Adobe Acrobat Pro to check your PDF meets the necessary standards. If you do not have Acrobat Pro, you can request it via the Service Desk or speak to the ONS Graphic Design team to fix certain issues.

You should also check your PDF is accessible with a screen reader.

These checks should all be carried out and any accessibility issues resolved before the document is uploaded.

PDF titles and file names

Clear and useful titles and file names help users understand what a PDF document contains without having to open and read the entire document. Without a descriptive title or clear file name, users may need to spend time searching the document to decide whether the content is relevant.

PDF documents should have titles and file names that describe the topic or purpose of the page. They should be:

• written in plain English and using house style
• using terms and phrases that reflect the language of our users
• as short as possible and no more than 31 characters
• frontloaded (with the most important information first)
• written in sentence case

They should not contain autogenerated sequences of letters or characters that provide little or no meaning.

We are constantly improving based on research and best practice. Any significant changes to our guidance are available on the Updates page.

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