If you manually register / import payments via your Upflow interface, or import them using the Upflow API, and you made a mistake -- don't worry, you can delete them :)
Deleting payments via the API
The Upflow API has a "Delete Payment" endpoint, through which you can remove any payment previously imported by you. As always, you can reference this payment by its Upflow ID or your own External ID (if initially imported).
Deleting payments via the UI
Provided you have the necessary permissions, you can delete payments directly from the UI in your "Transactions" tab by selecting 1 or more payments and hitting the "delete" option: