A prepaid-service system could record value or units purchased in advance and deduct the agreed amount when a service is delivered. The business needs to define whether credits represent money, sessions or a specific entitlement.
Customers should see purchases, usage and corrections clearly. Staff need approval controls for adjustments and refunds. Rules for expiry, transfer and cancellation require explicit terms and appropriate specialist review where needed.
Start with one service package and test partial use, a cancelled appointment and a duplicated deduction attempt. Keep planned bookings separate from completed redemptions. The system should support a traceable customer record without silently changing the meaning of credits or treating an internal balance as permission to offer regulated financial services.
Related reading: Purchase Order and Supplier Management Software.