How do I migrate tickets from one project to another?
All members of a project have full access to add, modify or delete tickets and other data (pages, comments) in that project and to move tickets from one project to another. Basically -- if you do not trust a user to manage the information in your project responsibly, do not grant them access.
You can transfer tickets from one project to another. If you do a search for a group of tickets, or search for a specific ticket number in a project, then there is an option to move the ticket(s) to another project.
You will not be able to keep the ticketing numbering the same. The newly moved tickets will just be numbered where the new project numbering currently ends.