Once you have both the Customer Down Payment account and item, the following is how to record your customer down payment:
1. From the Main Menu > Customers > Enter Sales Receipts to open Enter Sales Receipts window:
2. Fill in the Customer:Job, Date, Deposit to, & other fields as you enter Sales Receipt or Invoice except for the Item column where you need to enter the Customer Down payment item you just created above.
3. Enter the Amount of down payment or retainer.
4. Click Save & Close. This will increase both your bank account and other liability account.
To apply the down payment amount to invoice, just apply the Customer Down Payment item as a negative amount:
As you can see in the invoice, the Customer Down Payment item reduce the total amount due from customer without affecting the sales tax as it should be.