To find a posted Cashbook Payment go to Cashbook Payments and change the filter to Posted.

Locate the payment to reverse and click on the Spill Menu at the end of the row or ...More Options within the payment. Choose Reverse from the dropdown.

A confirmation window opens. Select Confirm to proceed.

The Cashbook Payment reverses and a new corresponding Reversal transaction is created for the same date as the original payment.

Select Back to return to the Cashbook Receipts screen. The two transactions are listed in the Cashbook Payments screen. Reversing arrows in the Payment column indicate the reversal.

To locate the matching transaction of a Reversal or Reversed  transaction, within either record go to Enquiry > Transactions.