3.3.4

3.3.4 Error Prevention (Legal, Financial, Data)

WCAG says:

For Web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:

• Reversible: Submissions are reversible.

• Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.

• Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.

When this is applicable

If there is a form.

Identify whether the submission causes serious consequences

Investigate the form to see if submitting it could result in:

• a legal commitment
• a financial transaction
• serious consequences from data loss or changes
• submitting unchecked responses for a test

How serious the consequences from data loss are depends on the circumstances:

• a misspelt name can be serious on a ticket for an international flight but not for a restaurant table booking
• on a social media app it may be serious to delete your whole account but less serious to delete a single post
• an incorrect date of birth can be serious when registering at a doctor’s surgery but may not be when signing up to a loyalty card

Before submitting the final stage of any forms, you may need to check with the website owner and make sure it’s clear you’re doing a test.

Check you can correct the data

Fill in the form and continue through the whole process.

Check the form provides a way to either:

• undo the action, including after you have submitted the whole form
• validate for errors and allow the user to correct them - it’s okay if this only happens at the very end before you submit the whole form
• review the data and make any changes before you submit the whole form

Best practice

When you can correct the data, check you don't need to fill everything in again.

Mobile app testing

No difference