Error Prevention (Legal, Financial, Data) (3.3.4 – Level AA)

‘Error Prevention (Legal, Financial, Data)’ requires websites to check, confirm and allow reversal of pages that cause important commitments.

Introduction

When a user is going through a process that results in a serious financial or legal commitment, or a change in data storage, it’s more important than ever to try and prevent mistakes. 

Although all users are susceptible to making mistakes, some disabilities and impairments can make users more likely to make errors. For example, people with reading or writing difficulties may type words incorrectly and those with motor disabilities may press keys in error.

Where the errors are legally binding, this can lead to serious consequences. 

How to Pass ‘Error Prevention’

If a process results in:

• a legal commitment;
• a financial commitment;
• modification or deletion of stored data; or
• submission of test responses

at least of of the following is true:

• submissions are reversible;
• input is checked for errors and users are given a chance to correct mistakes; or
• users are given a chance to review and confirm all input before submitting.

‘Error Prevention’ Tips

Remember this covers both submission of data and its deletion.

To make a submission or deletion reversible, provide users with a set time in which they can undo or change the action.

Check for input errors as users enter each field.

Replay all inputs to a user (or the information about to be deleted) and ask them to confirm they are correct before saving the submission.

Error Prevention (All) widens this guideline to include the submission and deletion of any data, so rather than judging if the submission is financial or legal, apply the solutions to all submissions and deletion requests.

See Also

• Error Identification
• Error Suggestion
• Error Prevention (All)
• Understanding Success Criterion 3.3.4 (W3C)