# Unsuccessful Payments (Exceptions)

This section considers the various exception scenarios when a payment cannot be successfully processed:

* [Rejects](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/rejects) - when a payment is rejected whilst it is being processed
* [Recall requests](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/recall-requests) - when the Source PSP asks for the funds transferred in an earlier successful payment to be returned
* [Returns](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/returns) - when the Destination PSP agrees to send the funds back to the Source PSP
* [Disputes](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/disputes) - when the Source PSP challenges details of the payment
* [Investigation & Enquiry](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/investigation-and-enquiry) - for establishing the status of payments where no confirmation was received (rare)
* [Reconciliation reports](https://docs.nexusglobalpayments.org/payment-processing/unsuccessful-payments-exceptions/reconciliation-reports)