Can I create a seperate instance of Jira to use with a business partner of ours?

[Software Registration]

We are partnering with a company and we want to use JIRA. Can we isolate what they can see without creating a separate instance of JIRA? Or is that necessary? We do not want our other projects to be viewable.

[Norbert Janssens]

You need to create a separate permission scheme and assign that to a project / projects in which you want to work with the other company. Please refer to https://confluence.atlassian.com/display/JIRA/Managing+Project+Permissions to get detailed informations about that. Additionally you can define security levels if you want to hide specific actions within that project(s).

[Joe Pitt]

You can control what the see by using groups and project roles. Just don't give the default jira-users group or any other group with logon rights to anything. And don't use 'everyone' in permission schemes.