How do I create a custom sub-task type in an existing project?

[PaladinEng]

As I'm building out my roadmap, child issues of stories are created automatically as default sub-task issues. I'd like to create a different type of subtask (Requirement) so that I can use the custom subtask instead.  

[Nic Brough -Adaptavist-]

In a company-managed project, talk to your admins - they can add new issue types to your project's issue type scheme, at either issue or sub-task level.

In a team-managed project, you are stuck, they only support a single sub-task type at the moment.

[PaladinEng]

Can a team-managed project be converted to a company-managed project? 

[Nic Brough -Adaptavist-]

No, the type cannot be changed.

You would have to create a new project of the right type and then move all the issues from the old into the new.

[Robert]

How would you do it on the company-managed project? I am the admin for our project, and I am able to add new issue types but not sub-types.

For context, we have created an issue type called Review that we only want created as sub-tasks to existing tickets. Right now, we have to create those Review tasks, and then add them to the task manually. This isn't awful for a single Review task but sometimes we need to do this for 6 or 7 people.