When you upgrade your account to a paid plan, you will become the Owner of a new workspace.
Any existing project members will also be added and listed in the Workspace Members page as a Reviewer with restricted access. This means they can only access projects and styleguides that they have been invited to — you can always change their roles and access levels anytime.
Workspace members can have four different roles with paid seats: Owner, Admin, Editor and Developer (only available on Organization and Enterprise plans). Members can also be assigned a Reviewer role, which is free of charge and does not count as a paid seat.
You can learn more about each role and how to manage workspace members here:
Adding new members
If you created a workspace from scratch, you will be the only member shown in your members' list. You can add more members by clicking on the “Invite Member” button; there you can assign roles and set their access level while inviting them.
Once you invite them, they will receive an email to access the workspace and register (if they have not signed up yet).
Keep in mind, you can invite more members than the number of seats you’ve paid for in your Workspace. When this happens, Zeplin will automatically increase your paid seat count, if the role assigned was Developer or higher.