A VPAT is a template, published by an industry body, that a supplier fills in to describe how a product meets accessibility standards; the completed document is the accessibility conformance report. Buyers, especially government ones, ask for it in procurement. It is a self-assessment unless an independent auditor produced it, which is the single most important thing to know about the genre. There is no ADA certification and no body that issues one.
What the report contains
A row per criterion with one of four verdicts (supports, partially supports, does not support, not applicable) and, for anything short of full support, an explanation. The explanations are the document: a report where every row says supports and nothing is explained is a report nobody who reads these believes.
Who asks for one, and what they do with it
Federal and state buyers, universities, health systems and increasingly large enterprises. The reviewer reads the partially-supports rows, checks whether the remarks describe a real limitation and a plan, and compares it against their own testing on a couple of pages. A report claiming perfection fails that comparison faster than an honest one.
Certification, and why nobody can sell it
No organisation certifies a website as ADA compliant, and a badge saying otherwise is a marketing device. What exists is an audit at a date against a standard, a conformance report, and a dated statement. On the worked example, an audit is $3,480 and the retest that proves the fixes landed is $1,392: those two documents are the evidence, and they are worth more than any certificate.
Questions people ask about accessibility conformance report
Do we need a VPAT?
Only if a buyer asks. If one has, write it against a real audit rather than from memory.
Can we write our own?
Yes, and many are self-assessed. Say so in the document: an honest self-assessment is credible and a dishonest independent claim is not.
How often should it be updated?
At each release that changes the interface, and at least annually alongside the statement.