1. Go to Set-Up → Receive Payments (or you can directly find this button in tool strip of billing screen).
2. Click on ‘Add Receive Payment’.
3. Select the customer from whom you are taking advance.
4. Select the payment mode (like cash, card, etc), enter the amount and click on ‘Save’ or ‘Save & Print’.
If you are taking advance from customer while creating a sales invoice for them, follow below steps :
1. Select the items being sold in billing screen.
2. Click on ‘Pay Now’
3. Select the payment mode and enter the total amount (invoice amount + advance amount).
4. Mark the checkbox ‘Save Returnable Amount as Customer Advance (F4)’ and click on ‘Save Invoice’ or ‘Save & Print Invoice’.