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WCAG 3.3.4: Error Prevention (Legal, Financial, Data)


Whenever we buy things online it's typical to see an order confirmation page before completing checkout. It provides, among other things, a valuable opportunity to reflect on your terrible financial decision-making. But this function isn't just so you can enjoy another look at the highly irresponsible purchase you've just made.

Everyone makes simple mistakes online now and again, so it's crucial that you do your due diligence and double-check that everything is in order, especially when money or other important personal information is involved. Take it from me, the man who once accidentally purchased a Dora the Explorer chair clearly manufactured for toddlers.

[Source: https://www.amazon.com/Delta-Children-Upholstered-Chair-Explorer/dp/B00PY02WUM/]

If your site lets users make financial transactions or legal commitments, changes or deletes user-entered data in data storage systems, or submits user test responses, one of the following should be true:

  • Reversible. Any data submitted or transactions made by the user are reversible.
  • Checked. Information entered by the user is checked for errors, and the user is in turn given an opportunity to make corrections.
  • Confirmed. A mechanism is provided that lets users review, confirm, and correct information before they finalize their submission or transaction.

Accessibility Concerns

Of course in the grand scheme of things, $40 lost on a kid's chair doesn't seem like such a disaster. Considering all the major transactions and sensitive information we enter online on a regular basis, the situation could've been a lot worse. I could've accidentally put a down payment on a Bigwheel.

This is a concern, however, for users with disabilities who may be more prone to mistakes for one reason or another. For instance, someone with a reading disability may have a tendency to mix up letters and numbers, or a person experiencing motor limitations might hit incorrect keys by mistake when inputting sensitive information. Accordingly, it's important to give users a chance to correct or undo transactions that could have potentially serious consequences.