When an invoice is sent to a customer without a Customer Portal account set up, an option to sign up will be available when viewing the invoice in a web browser. On the bottom left of the 'View Invoice' screen, you'll find a box allowing you to register for the Customer Portal for your business account.

This sign-up window will only show if your Customer Portal is NOT set up for your business account. The sign-up window will only show when you view the invoice by clicking on the 'PAY INVOICE' link in the email that was dispatched.
If you already have a contact associated with your business account, feel free to reach out to our Customer Service team. They’ll be happy to add additional contacts under your account, providing access to your transactional data for those contacts.