# Payment Process for the Source SAP

In the Source IPS, a Nexus payment will follow the following steps in relation to the S-SAP:

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1. After the S-IPS receives the payment instruction from the S-PSP, the S-IPS must ensure settlement and/or update the settlement obligations between the S-PSP and S-SAP, and
2. The S-IPS must send the payment instruction to the S-SAP for acceptance or rejection.
3. The S-SAP must:
   * review the payment instruction
   * apply sanctions screening (if required by local regulations, as this is a cross-border payment)
4. If the Source SAP is happy to accept the payment on behalf of the FXP (its customer), the following process will be followed:
   * In the case of a 4-step settlement process:
     * the S-SAP will respond with a status message to confirm that it will accept the payment, and credit the FXP’s account
     * the S-IPS will complete the transfer between the Source PSP and Source SAP, and then forward the payment instruction to Nexus
   * In the case of a 5-step settlement process:
     * The S-SAP will send a confirmation of acceptance to the S-IPS, and may (or may not) immediately credit the FXP’s account
     * The S-IPS will send the payment instruction to Nexus
     * Upon receiving a positive confirmation from Nexus, the S-IPS will complete the transfer between S-PSP and S-SAP, then send the S-SAP a confirmation that the payment has successfully reached the Creditor.
     * If the S-SAP did not already credit the FXP’s account, it will do so now.\
       The Source IPS will send the Source SAP a confirmation that the payment has been successful or rejected.

In case that the payment is rejected by either the D-SAP, D-IPS or D-PSP:

* the Source IPS will undo the reservation in the case of a 5-step settlement process, or, in the case of a 4-step settlement model, return the transaction by reversing the settlement obligations.
* the Source SAP must reverse the credit (if already made) to the FXP’s account.