Migration guide
Excel is flexible, but it is not a cashier, receipt printer, stock ledger or audit trail. As staff and products grow, formulas and versions become risk.
The business keeps the familiarity of spreadsheet imports and exports, while daily billing moves into a system designed for counters.
Run a test day, print receipts, close cash and verify reports before making Posnic the live counter.
Keep a backup/export from the old method so old invoices and balances can be checked later.
Billing habits change only when staff know sale, return, correction, payment and day-close rules.