The 365 area code is a notable part of Ontario's telecommunications network in Canada, serving the southern part of the province.

Introduction as an Overlay: The 365 area code was introduced as an overlay to the existing 905 and 289 area codes. This implementation, effective on March 25, 2013, was designed to provide additional numbering resources due to the high demand for telephone numbers in southern Ontario, particularly in the Greater Toronto Area and surrounding regions. The overlay approach allows existing 905 and 289 subscribers to retain their phone numbers, while new numbers can be assigned the 365 area code.

Geographic Coverage: The 365 area code, along with the 905 and 289 area codes, covers a significant portion of southern Ontario, including the suburban areas around Toronto and cities like Mississauga, Brampton, Hamilton, and Niagara Falls. This region is known for its dense population, economic activity, and cultural diversity, making efficient telecommunications a necessity.

Adoption of Ten-Digit Dialing: With the introduction of the 365 overlay, ten-digit dialing (area code + phone number) became mandatory for all local calls within the 905, 289, and 365 area codes. This requirement, aligning with the standard practice in regions with overlay area codes across Canada, was essential to manage the growing number of phone users and the consequent need for more telephone numbers in the densely populated region.

These facts about the 365 area code underscore its important role in supporting the telecommunications needs of southern Ontario. By providing additional numbering capacity and facilitating the transition to ten-digit dialing, the 365 area code ensures that the region's communication infrastructure can keep pace with its growth and evolving needs.