Adding a New Ship From Address
There are two ways to add a new Ship From address in PREP & SHIP.
One way is to select the drop down of Ship From Addresses in the upper right-hand corner of the PREP & SHIP Screen:
From the drop down, select, "Manage Locations."
That will take you to the Sources page where you can add a new Ship From address:
You could also navigate to the Sources page from the main menu under Report > Sources.
Merging Existing Ship From Addresses or Sources
To merge two or more existing ship from addresses or sources, hold the CTRL (or CMMD in Mac) key and select the sources or locations you wish to merge. With them highlighted, select "Merge Sources"