Success Criterion 3.3.4
Conformance level AA

3.3.4 · Error Prevention (Legal, Financial, Data)

Lesson overview · Error Prevention (Legal, Financial, Data)

In plain language

For legal, financial, or data-changing submissions: user must be able to review, correct, confirm — or undo.

Who it affects

Everyone in legal, financial, or data-changing flows — especially people prone to input mistakes.

How to check

Walk the checkout/signup/delete flows: look for a review step, editable summary, confirmation, or a reversal window.

Common misconception

This rule only applies to legal, financial, or data-deletion actions, not every form. But teams often either over-apply it everywhere or, more commonly, skip the review step on exactly the transactions that need it most.

Learn more

Understanding Understanding this success criterion (opens in a new tab)

Scenarios in this lesson

Binding Purchase Submitted With No Review Step Beforehand
One-Click Order Placed With No Chance to Review It First
Permanent Data Deletion With No Confirmation or Undo
Legal Commitment Submitted With No Review-and-Confirm Step
Review Page That Isn’t Actually Editable Before Final Submission
Financial Transfer Form That Never Confirms the Entered Details
Exam Answer Locked In Instantly With No Chance to Review
Timeout That Auto-Submits and Commits a Final Transaction
Confirmation Dialog That Never Shows What’s Being Confirmed