Invoices, transactions, reconciliation and safe payment handling.

Invoice states

Invoices move through controlled states such as Unpaid, Paid, Cancelled and Refunded. Callbacks identify the invoice, provider transaction, amount, fee, gateway and currency. Duplicate IDs and payments against terminal invoices are rejected.

Payment safety

• Never save PAN, CVV, track data or raw reusable card details.
• Prefer provider-hosted checkout or provider tokenization.
• Verify callback signatures before reconciliation.
• Use provider transaction IDs as idempotency keys.
• Record refunds locally only after provider success.

For bank transfer or other manual methods, staff should verify cleared funds before adding a transaction.