Documents published on GOV.UK must meet the GDS accessibility standards, including all PDF documents.
As a rule, you should try to publish as an HTML document instead of as PDF.
How to create an accessible PDF using Microsoft Word
This step by step guide assumes that you are using Microsoft Word version 10 or above.
Open your document and click 'Save As...', then select PDF.
You should see a box that says Options... below the main save menu.
Click on this and then check that the 'Document structure tags for accessibility' box is checked.
Then click Save, and you have created your accessible PDF.
If you have selected 'Minimise size' to create a PDF with a smaller file size, make sure to double-check that the 'Document structure' box is ticked.
The reason is that minimising the size of a document can sometimes uncheck the 'Document structure' tick box.