Every time you navigate away from a point of sale ticket, Heartland Retail moves the ticket to the "on hold" status.
If you go back to the point of sale and start a new ticket, rather than pulling up the previously started ticket, the original ticket will stay on hold indefinitely.
To find the tickets you have placed on hold, click the point of sale menu button (the button in the top left corner of the page with 3 horizontal lines) and click "find ticket." Change the status where it says "completed" to "on hold" and you will find your list of held tickets. You can select one to complete or void by clicking the ticket number.
If tickets are placed on hold with a credit card payment attached they will show up as having a "payment exception." For more information on payment exceptions, refer to What are the payment exceptions alerts on my sales dashboard?