Checkpoint 3.3.4 Error Prevention (Legal, Financial, Data)

For content that causes legal commitments or financial transactions for the user to occur, that modifies or deletes user-controllable data in data storage systems, or that submits user test responses, the user can reverse, correct or confirm the action. (Level AA)


The purpose of this checkpoint is to ensure users can avoid irreversible consequences that may occur when performing an action. This includes submitting financial transactions that cannot be reversed, deleting data that cannot be recovered, and purchasing items.

A disability can contribute to the possibility of making a mistake when performing a device-based action. For example, people with reading disabilities may transpose numbers and letters, and people who have motor disabilities may hit keys by mistake. Providing the ability to review and correct information or to reverse actions allows users to avoid mistakes which could have serious consequences.

To comply with this checkpoint, one of the following must be 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.

Refer to Understanding SC 3.3.4 for more information (external link to WCAG).

Development Techniques

Review the General techniques as well as other tabs applicable to your technology.  Prioritize the use of technology-specific techniques, and implement the General techniques as needed. You are always required to find, understand and implement accessible code techniques to meet the checkpoint. The documented techniques and supplements are not exhaustive; they illustrate acceptable ways to achieve the spirit of the checkpoint. If numbered, techniques are in order of preference, with recommended techniques listed first. Where used, IBM information that complements the WCAG techniques is indicated as supplemental.

General techniques

Instructions: Select the situation below that matches your content. Items in the described situation are sufficient techniques for applicable circumstances.

Situation A: If an application causes a legal transaction to occur, such as making a purchase or submitting an income tax return

Situation B: If an action causes information to be deleted

Situation C: If the content includes a testing application

Web (HTML, ARIA, CSS) techniques

There are no specific Web (HTML, ARIA, CSS) techniques for this checkpoint. Refer to the General techniques section.

Mobile Native (iOS) techniques

There are no specific Mobile Native iOS techniques for this checkpoint. Refer to the General techniques section.

Eclipse techniques

There are no specific Eclipse techniques for this checkpoint. Refer to the General techniques section.

Windows-based (MSAA+IA2) techniques

There are no specific Windows-based (MSAA+IA2) techniques for this checkpoint. Refer to the General techniques section.

Most links in this checklist reside outside at the Web Content Accessibility Guidelines (WCAG) 2.0. W3C Recommendation 11 December 2008:

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