Four decisions that make it usable.
These are the elements to specify and verify for this type of project.
Review logged-out and returning-customer states, mobile layouts, cart changes and clear validation. An administrator session cannot stand in for a buyer journey.
Inspect the complete style cascade before changing a critical control. Check floating elements, error messages and keyboard access at narrow widths.
A visible gateway does not prove settlement. Provider approval and any authorised transaction verification are separate from interface tests.
Choose meaningful checks, verify that they fail on controlled bad input and assign a responder. Set monitoring frequency and response terms explicitly.
What a useful review must show.
Evidence should record the environment, device and account state tested, the observed result and unresolved exceptions. Tests must avoid real charges unless separately authorised.
Set the expectation in writing.
Related brands retain their own provider accounts, receiving details and approval requirements. No credentials, payment routes or verification status are shared by implication.
Try the pattern before scoping the project.
Working prototypes use sample data and clearly identify what is simulated. A production engagement requires its own access, integration and acceptance checks.