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Card Payment Operation Rules

Purchase​

A Purchase is a standard payment where the submitted amount is fixed and finalized before approval.

Once approved, the payment is automatically captured (charged to the card) during the daily cutoff process.

Pre-Authorization​

A Pre-Authorization (Pre-Auth) is a non-standard payment where the submitted amount is an estimate.

Pre-Auth is typically used when the final amount is not known upfront - such as for hotel stays, fuel (petrol) purchases, or EV charging sessions.

  • The final amount can be adjusted (via increment or partial reversal) within a 30-day window.
  • You must manually capture the payment via the capture endpoint within 30 days after the pre-authorization is approved.
  • If the manual capture is not completed within this period, Nomupay will automatically reverse the pre-authorization.

Increment​

An Increment is used to increase the amount of a pre-authorization that has not yet been captured.

  • You can perform single or multiple increments when the final amount exceeds the originally authorized amount.
  • The currency must be the same as in the original pre-auth transaction.

Reversal​

A Reversal is used to void or cancel a payment that has not been captured.

It applies to both standard and pre-auth payments.

  • For standard payments, a reversal is only allowed before cutoff time.
  • For pre-auth payments, a reversal is allowed within 30 days or before the capture request is sent.
  • A reversal can be for the full amount or a partial amount.
    • Partial reversal can only be performed once (multiple partial reversals are not supported).
    • The reversal amount cannot exceed the total of the pre-auth and any increments.

Use cases:

  • Perform a full reversal if the authorization approval cannot be completed due to a timeout or system issue, or if the customer requests to cancel the transaction before cutoff time.
  • Perform a partial reversal if the final amount is lower than the pre-auth estimated amount.

The card and currency used must be the same as in the original payment.

Refund​

A Refund is used to cancel or return a payment that has already been captured.

It applies to both standard and pre-auth payments.

  • Refunds are allowed within 18 months after the payment is captured.
  • A refund can be full or partial.
    • Multiple partial refunds are supported, but the total refunded amount cannot exceed the captured amount.

The card and currency used must match the original payment.

Capture​

Capture is used to complete a pre-authorization payment once the final amount is known.

When you perform a capture, the customer's card is charged for the final amount.

  • The captured amount cannot exceed the sum of the pre-auth and any increments.
  • If the captured amount is lower, Nomupay will automatically perform a partial reversal to offset the difference.

The currency used must be the same as in the original payment.

Card Payment Cutoff​

The daily cut-off time can be configured on an hourly basis with Nomupay during merchant onboarding, per location.