548 Area Code – London, Ontario: Location, Time Zone & History

Southwestern Ontario's numbering plan has expanded in stages over seven decades. Area code 519 was introduced on November 1, 1953, as a split from area code 416, part of the original North American Numbering Plan rollout. As the region's population and phone usage grew, the CRTC layered overlay after overlay onto the same territory: area code 226 arrived in 2006, and area code 548 followed on June 4, 2015, approved under Telecom Decision 2013-575. That same decision reserved a further code, 382, for future relief, and it was ultimately activated in June 2023 after regulators projected the combined 226/519/548 supply would run out by mid-2024.

The 519/226/548/382 complex now covers London, Windsor, Kitchener, Waterloo, Guelph, and Sarnia. Windsor, sitting across the Detroit River from Michigan, has been considered the historic heart of Canada's auto industry since Ford opened its first Canadian plant there in 1904, and automotive manufacturing remains central to the region's economy alongside agriculture and agri-food processing, insurance and financial services, and advanced manufacturing.

Culturally, the territory is perhaps best known for Stratford's annual theatre festival. The Stratford Festival, North America's largest classical repertory theatre, has run continuously since 1953, the same year 519 itself was established.