Understandable · Level AA · Introduced in WCAG 2.0
WCAG 3.3.4: Error Prevention (Legal, Financial, Data)
Published by whatisADA / Grow Wild Agency · Updated
What this criterion means
For specified consequential submissions, provide a reversible action, error checking with a chance to correct, or review/confirmation with correction before finalizing. Covered cases include legal commitments, financial transactions, stored user-data changes and test responses.
A practical example
Before a customer places a paid order, show the items, quantities, delivery address and total with working Edit controls. The final action clearly commits the order after the customer has had a chance to correct it.
How to check it
- Identify submissions creating commitments, transactions, stored-data changes or test-response submission.
- Verify at least one permitted protection: reversal, checking with correction, or review/confirm/correct.
- Deliberately make a mistake and use the protection to recover before or after commitment as designed.
What can be missed
A confirmation dialog saying only “Are you sure?” may provide little opportunity to review the actual information. Check the complete workflow and whether corrections really reach the final submission.
Record your test
Use this worksheet to record what you actually checked. Notes stay on this device when you choose Save; they are not sent to us. Avoid personal or confidential information on shared devices.
These are your observations, not automated results or a conformance certificate. A complete evaluation needs appropriate scope, supported technologies, all applicable criteria and relevant page states.
Primary sources and scope
This is independent implementation guidance with original examples. The linked standard contains the full definitions, exceptions and conformance requirements. A criterion or checklist alone does not establish legal applicability or whole-site conformance.