Your invoicing system only allows me to make my business phone number the default contact information number on the invoice. The only issue is that my sub-accounts' Twilio numbers are the only "business number" they have. This causes the issue that their personal number is now being shared to their consumers via the invoice (the business number is their personal number because its the number they used to sign-up). In addition, when they attempt change the business number to their Twilio Number, they receive the error code "You cannot use your inbound number here, it will create a call loop."
All of this is to suggest that it would be fantastic if we could choose the Twilio number as the default number on the invoice.