Accessible PDF forms don’t start and stop with checkboxes and tables.
In Part 1 of our Accessible PDF Series, we showed how to build accessible tables with form fields in Adobe Acrobat Pro read it here.
In Part 2, we covered how to tag text fields, radio buttons, and checkboxes so screen reader users don’t get stuck read it here.
But what if everything still breaks for screen readers... even when your forms are “technically accessible”?
That’s where PDF tagging comes in.
In this third installment, we go beyond form field creation and into the structure that powers true accessibility. You’ll learn how to build a robust tag tree, fix reading order issues, apply alt text, set heading levels, and avoid the most common (and costly) tagging mistakes that lead to audit failures and federal risk.
Let’s get your PDFs properly tagged... for real accessibility, not just compliance.
What Happens When PDFs Aren’t Tagged Properly?
When tags are absent or broken, users with screen readers experience:
Entire sections skipped entirely.
Footers read before body text.
Lists that sound like long paragraphs.
Form fields read as "Field 1" or "Text Box 3".
Table data that loses context.
Screen Reader Example:
"Graphic. Graphic. Text box one. Text box three. End of document."
Instead of:
"Section 1. Application Form. Full Name. Address. Contact Information."
These failures are not just frustrating. They violate WCAG 2.1 AA and Section 508 requirements.
Step-by-Step: How to Correctly Tag PDFs for Accessibility Using Adobe Acrobat Pro
1. To begin, open Adobe Acrobat Pro and launch the file you want to edit.
2. Next, go to the Tools pane, search for the Accessibility tool, and click to open it.
Once the Accessibility pane is visible on the right side, click “Accessibility Check” and then “Start Checking” to run a scan of the document.
Review the results to identify any issues, such as missing tags or incorrect reading order.
3. If the document has no tag structure, click “Autotag Document” from the Accessibility panel. Then, open the Tags panel by navigating to View> Show/Hide &> Navigation Panes &> Tags, and verify that the tag tree includes basic elements such as headings, paragraphs, images, and tables.
4. To fix the reading order, click “Reading Order” under the Accessibility tools. Use this tool to select content blocks and assign the appropriate type (for example, “Heading 1,” “Text,” or “Figure”).
5. For images, locate the Figure tag in the Tags panel, right-click, choose Properties, and enter a descriptive Alternate Text. If the image is decorative, mark it as an artifact using the Reading Order tool.
When tagging images in a PDF, ensure each image has a Figure tag with appropriate alternative text (alt text) that clearly describes the image's purpose; if the image is purely decorative, mark it as an artifact to prevent screen readers from announcing it.
6. Next, confirm that all headings follow a proper hierarchy by checking that each heading is tagged as <H1>, <H2>, and so on. Right-click any tag and update its type via Properties if needed.
Aside from changing the heading level in the tag's properties, you can also double-click the heading tag to edit it directly or adjust the heading level using the "Reading Order" tool.
7. Review any lists in the document to ensure they are tagged properly using <L>, <LI>, <Lbl>, and <Body>. If the tagging is incorrect, fix it by manually editing the tag tree.
When tagging lists in a PDF, ensure they follow the correct structure by using <L>; for the list, <LI>; for each list item, & <Lb>; for the bullet or number, and <LBody>; for the item description so that that screen readers can interpret the content accurately.
8. Check the table structure in the Tags panel and make sure it includes < Table>, & <TR>, & <TH>, and & <TD> tags. If necessary, right-click the table and use Table Editor to define header cell scopes appropriately.
When tagging tables in a PDF, ensure each table includes proper structure tags such as <Table>, <TR>; for table rows, <TH> for header cells, and <TD>for data cells; also set the correct scope (row or column) for header cells to help screen readers convey the relationships between headers and data
accurately.
9. Set the document properties by going to File > Document Properties > Description and entering a document title. Then, under the Initial View tab, select “Document Title” to display it in the title bar.
10. In the Advanced tab, make sure the language is set (e.g., English).
11. If the PDF has more than one page, ensure users can navigate the form logically by opening the Page Thumbnails panel, right-clicking each page, selecting Page Properties, and setting the Tab Order to "Use Document Structure.
The Most Common Tagging Mistakes (and What They Break)
No tags applied at all
Heading levels out of order
Lists missing structure
Tables missing headers or scope
No alt text for images
No document language
Tab order not defined
DARTSuite Audit Insight: Lists and tables account for 40% of all tagging issues across state agency and university audits.
The risk? Accessibility violations, failed procurements, lawsuits, and federal compliance investigations.
Need Help Tagging at Scale?
We built DARTSuite to help agencies handle complex PDF remediation without bottlenecks:
Expert tagging and remediation
Training for internal teams
End-to-end WCAG and Section 508 compliance
Schedule a PDF audit consultation
Explore More PDF Accessibility Guides
Want to go deeper? Visit our full Document Accessibility blog archive for practical How-To's, compliance strategies, and remediation tips that your agency can use today: