If you have a sale that you need to pause and continue later on, you can Park that sale easily using ACE. 

Step-by-step guide

1. When you are on the Sales screen, add a few items and a customer as you usually would.

2. When you need to park the sale, click Change [F12].

3. On the Change screen, select Park Sale [F12].

You can Recall this sale at any time. To recall a sale, simply go to the sales screen, press Change [F12], and the most recent parked sale will be open if you press Recall Sale [F12]. To see a list of your previously parked sales, orders, and so on, see How to View an Existing Layaway, Order, Work Order, or Quote. You can park as many sales as you find necessary.