What is an area code?
An area code is the three-digit prefix at the start of a North American phone number, which usually ties the number to a geographic region.
Why it matters for sales teams
Prospects read the area code before they answer. A familiar code looks like a nearby caller, while an unfamiliar one tells them the call comes from far away. That is one reason teams call from local numbers.
The area code is also a hint about the prospect's time zone, which matters for calling time restrictions. It is only a hint. People keep their mobile numbers when they move, so the code shows where a number was assigned, not where its owner is today.
Example
A rep in Chicago calls a prospect whose mobile number starts with 512, a Texas area code. The prospect moved to Denver years ago and kept the number. A call at 8:30 a.m. Texas time reaches the prospect at 7:30 a.m. where they actually are.
Area code vs overlay area code
Some regions have more than one area code for the same place. An overlay area code is added on top of an existing one instead of splitting the region. Toll-free numbers use three-digit codes too, but those are not tied to a place.