• Success Criterion 3.3.3
  • Conformance level AA

Taken Username With No Suggested Alternatives Offered

3.3.3 — Error Suggestion

Scenario

Setting

A ride-hailing app's trip booking screen

What’s wrong

Username taken but no availability alternatives or guidance offered where feasible.

Example 

<!-- shown when booking a shared/pooled ride, before matching with other riders -->
<label for="username">Public display name for this ride</label>
<input id="username" value="alexrivera">
<p role="alert">Username already taken.</p>

Why it matters

A rider trying to book a pooled ride before their pickup window closes gets stuck retyping random display names one at a time instead of picking from a suggestion.

How to test

Enter a taken username: if there's no suggestion of available alternatives or guidance where that's feasible, it fails.

How to fix

When the system can check availability, offer at least one or two ready alternatives in the same message so booking a shared ride doesn't stall on a naming collision.

<label for="username">Public display name for this ride</label>
<input id="username" value="alexrivera" aria-describedby="username-error">
<p id="username-error" role="alert">alexrivera is taken. Try alexrivera92 or alex.rivera instead.</p>

Outcome

The rider taps a suggested display name and finishes booking the shared trip before the match window closes.

Who is affected

People with cognitive disabilities and users under time pressure who benefit from ready-made alternatives instead of open-ended guessing.

Learn more

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