No Redundant Entry
MUST: Within one process (checkout, signup, application), never ask for information the user already entered: auto-populate it, or make it selectable — a "same as shipping" checkbox, a dropdown of addresses already given, or the value shown next to the field. WCAG SC 3.3.7 Redundant Entry, Level A. Browser autofill does NOT satisfy it (that is SC 1.3.5); "re-enter your email to confirm" is the classic violation. Exceptions are narrow: essential re-entry, security, or stale data.
Never ask for the same information twice in one process: auto-populate it, or let the user select it
Bad
Good
Why it matters
SC 3.3.7 Redundant Entry (Level A, WCAG 2.2) is about a single process — one checkout, one signup, one application — not about sessions. That is what separates it from forms-autocomplete, which is about the autocomplete attribute and browser autofill across visits (SC 1.3.5 Identify Input Purpose). The Understanding document is explicit that browser autofill does not satisfy this criterion: the content itself must carry the value forward.
So a step-2 billing form that is an empty duplicate of the step-1 shipping form fails, even if every field is perfectly marked up for autofill. Satisfy it by auto-populating the second form, or by making the value available to select — a "same as shipping" checkbox, a dropdown of addresses already entered, or the value visibly printed next to the field so it can be copied.
"Re-enter your email to confirm" is the classic violation: it exists to catch typos, but the previous value is right there on the page, so show it instead of demanding it again. The exceptions are narrow: re-entry that is essential (a password, a memory test), security-required re-entry, or data that has gone stale.