To create a Group or Business in TM3 (Web) select the Contacts area of TM3
Fig 1 - Contacts Desktop
To the right side you will have an Add New button. clicking this will allow you to create a Business / Group.
Fig 2 - Add new Contact
Complete the details as needed; The name should have some resemblance to the Pronto group. For example, for BUPA Self Pay creating a Group / Business of the same name is optimal.
Fig 3 - New Business
If you need to create new charges for this Business / Group see below;