To delete a transaction just click Bank > View/Add Transactions button > Click on a transaction > Click Delete button. Please be aware that deleting a transaction that has been previously reconciled will cause that and subsequent reconciliations to be incorrect, you will have to re-reconcile all reconciliations thereafter. If a transaction is associated to an invoice or a purchase you will be taken to the relevant invoice or purchase receipt, in that screen you will need to click Delete Payment to delete it. If it is a bank transaction then you'll be taken to the following screen where you can click Delete button.