3.3.4: Error Prevention (Legal, Financial, Data)

What it means

For legal, financial, or data submissions, users must be able to review, confirm, and correct before final commit — or be able to reverse the submission. Prevents costly irreversible mistakes.

Checkout, contracts, and account deletion need safeguards.

How to fix it

• Add a review step showing all entries before payment or signature.
• Let users edit previous steps in a wizard.
• Provide undo or cancellation window for financial transactions where feasible.
• Require explicit confirmation for delete-account actions.

Quick examples

• Good: Checkout shows an order review page before charging the card.
• Bad: One-click submit sends a legally binding form with no review step.
• Good: Users can go back to fix shipping before confirming purchase.
• Bad: Deleting an account happens immediately with no confirmation dialog.