Within Teamwork, you can invite people to your site through the site-level People area.
In the top right of this screen, you will see options to add users.
The Invite Users button gives you the option to invite people as users to log in to your site, and interact with the projects you add them to.
This is a quick way to invite multiple new users to your site at the same time, add them all to a particular set of projects, and write a custom message they will all see within their invite email.
On the Who To Invite tab, you can enter in each person's first name, last name and email address. Each time you complete a line, another will appear.
Once you have added the details for at least one person, you will also be able to choose the company they will belong to, or add a new company directly.
Click the green button at the bottom to go to the projects list. Here, you will be able to select which projects the user(s) are added to.
You can use the checkboxes next to each project to select them individually, or use the Select All button at the bottom.
To quickly find a specific project you can start typing its name in the search field.
You can also add a new project directly from this screen using the Add Project button.
After you have chosen the projects you can use the Permissions options at the bottom to quickly set up all of your new users so they are either project or site administrators, or whether they have the separate individual permissions to add users or create projects.
Click the green button at the bottom to go to the Message screen.
You can add a message which will be included in your invite to the new users. If you have already set a default custom message to be included in your invites you will automatically see that here. You can overwrite that message, or customize it for this particular set of invites.
Click the Send Invites button in the bottom right, which will show how many users in total will be invited.
For more information, see: Adding Users