Afterwards, a new account will be created with each company name. We'll send an email for each company with its respective user key attached. That user key needs to be loaded into the Tool.
You must have at least one separate customer database for each parent company. To download a new customer database, go to the Tool's "Settings & Support" sheet -> "Customer Databases" section -> "Add or Remove Customer Database" link -> "Download New Customer Database" button. The database downloaded will only work with the Active (Parent) Company currently selected. You can name the database to reflect the company, e.g. "OnGrid CustData Company A.xls" for Company A. To switch between databases, go to the top of the Inputs sheet, above "Load Customer Data", and use the drop-down list under "Active Customer Database".
At present there is no way to have multiple customers assigned to different parent companies in one customer database. There's also no easy way to individually transfer customers from one parent company to another.