# Reference Number Handling in POS

### 1. Normal Sale Invoices (linked to Advance/Proforma invoices)

- The POS allows the operator to enter a reference number when finalizing the invoice.
- The system automatically validates and tracks the reference number to ensure consistency with the linked advance/proforma invoice.

### 2. Refund and Copy Invoices

- The POS requires a reference number to be entered.
- This ensures accurate linkage to the original invoice and prevents submission errors.

### Automation and Compliance

- All reference numbers are automatically validated by the POS against FRCS TaxCore.
- The system prevents incorrect submissions, minimizing user error, as it operates in real-time online mode with TaxCore.