This article shows how to undo, delete, or remove a sale/transaction.
Go to Manager > Sales.
Open the sale you wish to remove. In the Transaction Details pane, click the Void button to undo the transaction. If there is an appointment associated with the sale, the appointment will turn to an unpaid state, and can be edited or removed if necessary.
If you click the Refund button instead, the sale will be processed as a refund and the appointment will remain in a complete/paid state.
The button may be labeled as Undo instead of Void. This will function the same. If you don't see either button, you can reach out for help by clicking Support > Contact us in your Phorest system.
From here you may want to look at How to edit a sale after it's complete.