3.3.4 Error Prevention (Legal, Financial, Data)

MCS Accessibility Team

MCS Accessibility Team
Last Updated July 23, 2020

The following directions are part of a full step-by-step guide to making a HubSpot website WCAG 2.1 AA compliant. These recommendations are intended for websites managed on the HubSpot CMS but can be adapted for other content management systems.

Principle: Understandable
Information and the operation of user interface must be understandable.
Guideline: Input Assistance
Help users avoid and correct mistakes.

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:

  1. Reversible: Submissions are reversible.
  2. Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.
  3. Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.

View Official WCAG 2.1 Compliance Techniques


This criteria relates to performing actions that are either irreversible or cause serious consequences if done incorrectly. Errors involving transactions that are immediate and cannot be changed afterwards can be severely detrimental to the user. This includes items such as financial or legal transactions, as well as database management. A user with a developmental or motor disability may have a higher chance of making a mistake while filling out the necessary information. 

For example, a user books a hotel room that has a no-refund policy and select the wrong check-in date. Once the transaction is complete, they could end up losing that money.

As another example, if a user is making changes to a client database and accidentally deletes an important contact's information, if there is no way to recover the data, it can be problematic for their business.

This criteria requires providing the opportunity for users to be able to identify and correct any mistakes.

Recommended Solutions

  • Detail Confirmation: When someone submits a form for a financial or legal transaction, or one that alters a database item, prior to final submission, a confirmation page should appear for the user to review all pertinent information.

    If an error is identified, the user should be able to make any necessary changes before reviewing everything again and completing the transaction.

  • Window of Time to Make Changes: Submission of legal documents often requires many details and mistakes can cause devastating consequences. Once documents have been submitted, if possible, provide the user with a window of time in which they can adjust the documentation or cancel the submission entirely.

  • Deletion Recovery: If an important detail in a database is deleted, there should be a way for a user to recover that information.

  • Check Box to Confirm: Along with a submit button, a helpful tool may be to also include a checkbox above it requesting that the user reviews all the information they entered and confirm they have checked that everything is accurate.

For more information, please visit the official W3C article: Understanding 3.3.4 Error Prevention (Legal, Financial, Data)


Let us know if we can help you address this specific WCAG Recommendation.