Billing Account Administrators do not typically add users to their accounts. Instead, a user joins by accepting an invitation to an application in an account.
However, Billing Account Administrators control who can create applications within your account. Using two different tabs in Manage your billing account, Billing Account Administrators can:
Each time an application manager invites a user to share an application, QuickBase adds that user to the Users with Access tab (in Manage your billing account).

You can quickly grant Create permissions to any user listed here. Simply select the users you want and click Grant Permission to Create Apps. QuickBase automatically grants create permissions to all selected users. In addition, QuickBase adds the selected users to the Permissions tab.

On the Permissions tab, you'll see that the users were given Create permissions only; they were not granted Full Management or Support permissions within the Billing Account. (Users with Full Management or Support permissions can grant other users Create permissions within the billing account.) You can grant Full Management or Support permissions on the Permissions tab, if you wish.
On your My QuickBase page, click Manage your billing account, and then click the Users with Access tab.
Select the users who should be able to create applications.
Click Grant Permission to Create Apps. QuickBase grants Create permissions and adds these users to the Permissions tab.
If you've granted a user Create permissions on the Users with Access tab, QuickBase automatically adds them to the Permissions tab. Here, you can decide whether you want to also grant specific users Full Management permissions on the billing account.
You can also add new users or groups directly to this tab. By adding new users or groups and setting their permissions to Create, you are granting QuickBase users the right to create applications in your Billing Account, even if they've not been invited to any existing apps within the account.
On your My QuickBase page, click Manage your billing account, and then click the Permissions tab.
Within the Create Applications column for user or group who should be able to create applications and click the dropdown and select Create. (If you don't see the person, click the Add User button and, select the person in the User Picker that appears.)
Optional: Within the Manage Account column for that user or group, click the dropdown and select Full Management or Support.
Click Save Changes.
Note: If a person should be able to create applications, but not have access to your billing account settings, make sure that the dropdown in the Manage Account column is set to No. That column lets you add or change billing account administrators.
If your company's email domain is registered with QuickBase, you can follow these steps to give Create permissions to all users in your company. (Learn how to register your company's email domain with QuickBase.)
To allow all users in your company to create applications:
On your My QuickBase page, click Manage your billing account, and then click the Permissions tab.
Click Add Email Domain Group.
QuickBase displays the list
of all email domains that are registered for your company, as shown
below:

Select one or more email domains (for example, @mycompany.com) from the list that appears.
Click Add.
Click Save Changes.
Any user with the specified email domain will be able to create applications in your billing account.
To remove application creation permissions:
On your My QuickBase page, click Manage your billing account, and then click the Permissions tab.
Locate the user whose creative powers you'd like to restrict.
Click the dropdown in the Create Applications column and select No.
Click Save Changes.