True. For traditional phone companies, what is a local call and what is not a local call is based on the exchange part of the number, not the area code.

Some background on how a number is broken down, for those who do not know.

+1 713-555-1212
1 = Country Code
713 = Area Code
555 = Exchange
1212 = Phone Number

Calls from one exchange to another exchange may or may not be long distance, even if in the same area code.

(Before phones were so widespread, technically the last 4 digits were your phone number, and the exchange and area code specified what city's exchange needed to be connected to, in order to reach that number).