What is a phone carrier?
A phone carrier is the company that provides service for a phone number and carries the calls made to and from it over its network.
Why it matters for sales teams
The carrier on the receiving end decides what a prospect sees. It runs or chooses the analytics that can put a label like Spam Likely on a call or block it. Different carriers work with different analytics partners and use different label wording, so one number can be treated differently on different networks.
Carriers also sit at the start of a call. Under STIR/SHAKEN, the originating carrier signs the caller ID and other carriers validate it before the call reaches the recipient.
Example
A rep's call to a prospect passes from the rep's provider, through other carriers, to the prospect's mobile carrier. That last carrier checks the caller ID authentication, applies its analytics and decides whether to deliver the call as normal, with a label, or not at all.
Phone carrier vs line type
The carrier is who provides the service. Line type is what kind of service it is, such as mobile, landline or VoIP. When a number is ported, its carrier can change while the number stays the same.