Local browser history is convenient for a quick prototype, but a real service needs account-based history. A database-backed history lets users return to previous checks across devices and sessions.
The history should store the checked IMEI, the public summary, timestamps, provider status and a reference to the user account when available. Sensitive provider payloads should be limited to what the service truly needs.
Designing this layer early makes it easier to add credits, invoices, saved reports and team accounts without changing the basic IMEI checking flow.