In the event that you need to charge a customer a different amount than their monthly payment or a one-time cost, you can generate a manual payment.
In the Payment History section of a Customers Details there is a button you can select to create a Manual Payment.
Selecting this button will create a new pop-up window for the customer you are creating a new payment for. Here you can enter the amount you wish to charge the customer and add a description to be shown on the customers bank statement.
Once the manual payment has been created the charge will display as usual in the customers payment history.