Within Teamwork, you can add multiple people quickly to your site as users or contacts by importing them in a CSV or vCard format.
Go to the People tab at the top of your site and select the People subsection.
From there, click the options button (three dots) in the top right corner, where you will see the import options.
The option to import people as users. The import must be in a specific format; example files are available once you select the import function. Imported users are not sent an invite email but you can send them one later.
The option to import people as contacts. The import must be in a specific format; example files are available once you select the import function.
You can also import users and contacts via the Import tab of your site settings.
Select Settings from your profile dropdown menu.
Under the Import tab, you will see options at the bottom for importing users and contacts.
Selecting Import will open a modal where you can choose a CSV or vCard file from your computer.
For more information, see: Quickly Inviting Multiple People to Your Site