Right now, "default phone number" is set at the account level in the Phone Number settings. What this means is that the sub-account has a single default phone number.

This is fine as a fallback setting. But we need the ability to choose a default phone number on the contact level.

For instance, if I have a California phone number, I want to be able to assign that phone number to all my California contacts as the default when sending those contacts SMS or making calls. And then maybe I also have a New York phone number as well, and I want that number as the default for SMS and calls for New York contacts. Etc.

With this feature, we can purchase and have many phone numbers that are local to different service areas, and then assign these numbers as the default for specific contacts in those areas.