Yes. Should you wish to, you can prevent users from accessing your Business Account.
If a user has been onboarded, you are able to Deactivate that user. Deactivating the user will prevent the user from being able to access their account/the Business Account. All billing associated with the user seat will stop and the users details will not be usable anymore e.g. cannot be a sender, cannot assign programs to them etc...
NOTE: We currently do not allow a full deletion of the user from your Business Account - deactivating the user is considered a soft delete. This is because deleting a user from your account would delete all data associated with that user, data which is important to your Business Account e.g. programs they have run, contacts they uploaded etc...
An exception to this is when an invited user has not yet completed their onboarding process to claim their user seat on your Business Account. Where this is the case, you are able to permanently delete the invited user.
You are also able to temporarily suspend a user on your Business Account. This will prevent the user from being able to access their user seat/the Business Account. Billing will continue for suspended user seats. You may wish to suspend a user for example if you feel their user account has been compromised so that they can then reset their password.
These actions can only be done by Primary Account Admin users or Account Admin level users.
For more detail see: How to delete, temporarily deactivate or suspend a user.
NOTE: these actions apply to specific users. You can also Delete or Deactivate your Business Account (affecting all users associated with the Business Account).
See also FAQ: Can I permanently delete or temporarily disable/deactivate my Hypadrive.ai Business Account?