When you sign up for a WorkPack account, the first message on your dashboard says that WorkPack is a collaborative tool and you should invite other members of your project team to WorkPack so you can start working with them.
Click on the dashboard message to open a form for inviting new users. Note that the message above will only be visible to the administrator of WorkPack account. By default, user who creates a new company account on WorkPack is the administrator. However this can be changed from the user master page.
The option to invite team members can also be accessed from the Admin section of the sidebar menu.
When new users are invited to join WorkPack as described above, they will receive an invite email from WorkPack with a registration link. They can register through that link to join your team's account on WorkPack.