If you need to copy items from one or more maps onto a single map (e.g. to combine into a main map) then before you start, make sure that you have opened the main map and the other maps that you are taking parcels from in one instance of PTMapper.
If you double click on a map file it will open an instance of PTMapper for each map and you won’t be able to copy between maps.
Once you have all the relevant maps open, each map will have a tab with it’s map file name displayed (at the top of the screen just under the buttons). Switch to the first map that you plan to take parcels from by clicking the tab which displays the map file name.

You have two options to copy parcels from the map:
1) If you want to copy ALL parcels from a map layer
Click on “Select layer objects” (this selects ALL the objects on that layer)
Click on EDIT and then COPY
Click the tab for the main map to switch to it
Click on EDIT and then PASTE
NOTE: If you want to copy ALL parcels from several different layers at once then hold down a Control key and click on each map layer on the left side of the screen (they should each turn blue as you select them), then right click and choose “Select layer objects” (this selects ALL objects on ALL selected layers).
2) If you only want to copy some parcels from a map layer (or layers)