You may wish to take payment in advance.
To do this, click "Patients" then select the patient for whom you would like to create an advance payment.
Then click "Invoices" on the left hand side and you will see the below page, click on the arrow new to new and select "Payment on account" from the dropdown list as circled below:
You will then be led to the page below, select the payment type and enter an amount in the "Amount" section:
Once you click "Save" you will see that the payment has been added, in this example "Payment on account #21" has been created:
You will be able to delete this payment by clicking "..." and selecting "Delete" as below:
If you would like to use this advance payment on this account to pay one of the outstanding invoices then click "Pay" on that invoice as below:
You will see the page below. In the "Payment type" field you will need to select "Pay from account (£500.00)" and click "Save" as below:
You will be taken to the following page which will also reduce the amount of credit on the account as circled below: