If a customer wants to make pre-payment then a credit invoice can be created so that you can allocate this towards an invoice later down the track. In order for this to work the customer will need to be set as an ACCOUNT CUSTOMER.
Here is a guide on How to change your customer from a Cash customer to and Account Customer
1. Click on the '+' icon located next to the main search bar in Workshop Software and select 'Customer Invoice' from the dropdown box.
2. Search for the customer using the search field at the top right of the page and double click on the customer you are looking for.
3. Enter in the invoice details; ensure that your select 'Credit' from the 'Invoice Type' dropdown menu.
4. Click on the blue 'Process' button located on the bottom right hand corner of the page to finalise the invoice:
5. The customer will now have an unapplied credit for the amount of the invoice noted on it's profile:
Here is a guide on how to apply a credit to an invoice