Giving every employee the same full-access login is the easiest setup on day one and one of the more common regrets a few months in — usually right after a discrepancy nobody can trace back to a specific person.
Cashier: sales only, nothing structural
Someone ringing up transactions typically doesn't need access to pricing changes, financial reports, or inventory adjustments — limiting their access to sales entry reduces both accidental mistakes and any temptation for deliberate ones.
Manager: broader access, still short of full control
A manager often needs to see reports, adjust inventory, and process refunds, but full financial visibility (like profit margins or full historical revenue) might reasonably stay reserved for the owner, depending on how much trust and responsibility the role carries.
Owner/admin: full access, ideally on a personal login
The account with full financial visibility and system settings access should be tied to a specific person, not a shared password everyone knows — this matters if you ever need to trace who changed a setting or approved a discount.
Individual logins matter more than the specific role structure
Even a simple two-tier system (cashier vs admin) is a meaningful improvement over one shared login for everyone — the specific role names matter less than each person having their own traceable access.
Review access periodically, not just once at setup
As staff roles change or people leave, permissions should be updated accordingly — a former employee's account still active months later is an easily avoidable risk.