If you want to invite multiple users at once, you can do so by adding multiple email addresses to the invite form email field.  

By Email

Step 1. Team settings

Click your team's name to toggle the dropdown menu. Select Team settings.

Once in the Team members page, click Invite teammates.

 

Step 2. Select role and enter emails

Select the role of the users you want to add, then choose Email contacts. 

In the Enter emails field, type a comma separated list of your email contacts. After which, hit enter, or click the Add email option. Click Next to continue.
 

Step 3. Send invite

On the Team member onboarding, you can choose where to direct your new users and add an optional message to make things a bit more personal. Hit Send invites after you're done.

 

Without Invitation

For the easiest way to add users, allow them to join without an invitation.

1. Click on the team name on the top left. 
2. Choose Team settings.
3. Click on Admin settings.

1. From there, select the options to Allow Slack users to join without an invitation and Allow Google Workspace users to join without an invitiation.

Then, you can direct them to app.tettra.co where they can sign in to create a new account.
 

Related

• Account management overview
• How to add guests and users by email