E-signatures and accessible PDFs: what Acrobat Sign and DocuSign preserve, and why remediation must come first

Contracts, consent forms, HR documents, and approvals are increasingly signed electronically, and the signed PDF is often the version that is filed, shared, or published. Whether that version is accessible depends on what went into the signing platform and on what the platform does to it. This guide sets out what the two dominant platforms document, why a signature freezes the file, and the order of operations that keeps the signed record accessible.

Acrobat Sign: tags in, tags out

Adobe's documentation for Acrobat Sign is unusually direct. Tagging "is only supported in Acrobat Sign when a properly tagged PDF is uploaded as the source document". When an accessible document is used as an agreement, "the original document tagging is preserved and any content added to a field by a participant is also properly tagged, resulting in a fully accessible final document". The note that follows is the important one: "Acrobat Sign can not create an accessible PDF from a source document that is not already accessible." Adobe's recommended workflow is to design an accessible Word document, convert it to PDF, remediate the PDF, then add or edit the form fields, and only then upload it. Tagged output must also be switched on at the account level, under Account Settings > Global Settings > Accessible PDFs, with Enable Tagged PDF Generation selected.

Docusign: an accessible signing experience, and a file to check

Docusign's accessibility hub states that its products aim to conform to WCAG 2.2 Level AA, that it tests with people with disabilities and an independent accessibility partner, and it publishes Voluntary Product Accessibility Templates for its sending and signing experiences. For Windows it recommends NVDA with Chrome or Firefox. It also provides sender guidance titled "Sending Accessible Envelopes Part 1: Preparing an Accessible PDF with Form Field Transformation", which is the same principle as Adobe's: the accessibility of the completed document starts with an accessible source and properly named fields. Independently, community threads report completed Docusign documents failing tagged-annotation checks, with the envelope identifier stamp cited as an untagged element. The practical conclusion is not that one platform is better, but that the completed file is a new file and must be checked like any other.

Why you cannot fix it after signing

A digital signature is a cryptographic hash of the signed bytes plus a certificate. Any change to those bytes, including adding a tag, editing alt text, or setting the document language, means the hash no longer matches and viewers report that the document has been altered since it was signed. That is the signature doing its job. PDF/UA-1 recognises the constraint: the Matterhorn Protocol's digital signatures checkpoint (23-001) requires no specific test but notes that the form field provisions still apply. So the rule is simple: remediate, then add fields, then sign, then verify. If a signed document turns out to be inaccessible, the options are to provide an accessible copy of the unsigned master alongside the signed record, to re-execute the signature on a remediated file, or to provide the content in another accessible format on request. DocAccessible's free tag editor refuses signed PDFs rather than silently invalidating a signature for exactly this reason.

The order of operations

1. Author accessibly. Headings, real lists, table headers, alt text, title, and language in the source document, then export with tags; see which apps export tagged PDFs.
2. Remediate the PDF. Check it with a tag viewer and checker, fix reading order and structure, and run a screen reader pass; the 15-point checklist covers the manual items.
3. Add fields, then name them. Every field, including the signature field, needs a tooltip that matches its label, a place in the tag tree, and a tab position that follows the reading order. Section508.gov's guidance for signature fields is to "add tooltips that match the label or instruction, and validate that the tab order matches the visual/logical order". See accessible PDF forms.
4. Configure the platform. Turn on tagged output where the platform requires it (Acrobat Sign) and use the platform's field-mapping route so your named fields are used rather than replaced.
5. Sign.
6. Verify the completed file. Open the executed PDF in the free tag viewer and checker, and check that the signature block, the platform's stamps, and any added pages have not broken the structure. Record the result with the document.

Handwritten and scanned signatures

Printing a document, signing it by hand, and scanning it back destroys the accessible version: the scan is an image with no text layer and no structure. Where a wet signature is unavoidable, keep the accessible unsigned master and treat the scan as the record. Where a scanned signature block must appear in an otherwise accessible PDF, Section508.gov's guidance is to mark the entire signature block as a figure and put all of its text (name, title, date) in the alternative text, particularly where the signature overlaps document text. A scanned document that has to be made accessible after the fact needs text recovery first; the free scanned-PDF tool detects image-only pages and routes them correctly.

Procurement

Section508.gov states that electronic signature software procured by a federal agency must conform with the Revised 508 Standards for software and websites, and any organisation can ask for the same evidence: the platform's current Accessibility Conformance Report for the signing experience, and a statement of what happens to tags in completed documents. The VPAT and ACR guide explains how to read what comes back.

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. Adobe Acrobat Sign: Create accessible PDFs (updated August 2, 2023) . Tag preservation only for tagged sources, participant content tagging, the workflow, and the Enable Tagged PDF Generation setting.
2. Docusign Accessibility Hub . WCAG 2.2 AA target, VPATs, recommended screen reader combinations, and the accessible envelope guidance.
3. Docusign Community: What element is not tagged in these documents? . Community report of a completed envelope failing a tagged-annotation check.
4. Section508.gov: Electronic Signatures . Tooltips and tab order for signature fields, scanned signature blocks as figures, and procurement of signing software.
5. PDF Association: Matterhorn Protocol 1.1 (PDF) . Checkpoint 23, digital signatures.