Area Code Atlas

NPA 416 introduced as original area code

Area code 416 was assigned in 1947 as one of the original North American area codes covering southern Ontario including Toronto and the Golden Horseshoe region. It was part of the initial rollout of the North American Numbering Plan.

Establishment of area code 519

In 1953, area code 519 was established in southwestern Ontario through a remapping of the western portion of 416 and the southwestern portion of 613. This created a new numbering plan area to serve the region.

First split of NPA 416

The first split of area code 416 occurred in 1953, reducing its geographic reach as its western portion was combined with part of 613 to form area code 519. This reduced 416 to the core of the Golden Horseshoe region.

NPA 519 split from 416 and 613

In 1953, the southwestern portion of area code 613 was combined with part of 416 to form area code 519, reducing the coverage of 613 in Ontario.

NANP - INTERCHANGEABLE CENTRAL OFFICE CODES IN THE TORONTO, ONTARIO, CANADA 416 NPA

NANP-SPLIT OF 416 (ONTARIO, CANADA) NUMBERING PLAN AREA (NPA)

Area code 905 introduced for Golden Horseshoe region

Area code 905 was created in October 1993 as a split from area code 416 to serve the Golden Horseshoe region surrounding Lake Ontario in Southern Ontario, Canada. Automatic number identification started operation on October 11, 1992, and the new area code entered service on October 11, 1993.

Establishment of area code 905 in a split from 416

In October 1993, area code 905 was established in a split from area code 416, serving the Golden Horseshoe region surrounding Toronto. The split was implemented to address rapid growth and number exhaustion in the Toronto metropolitan area.

NPA 905 split from 416

Area code 905 was created on October 2, 1993, by splitting the 416 numbering plan area. The 416 area was reduced to Metro Toronto, while 905 served the surrounding Golden Horseshoe suburbs.

Permissive dialing period begins for 416 and 905

Permissive dialing for both area codes 416 and 905 began on October 2, 1993, allowing calls to be completed using either code during the transition period following the split. This period was intended to ease the transition after the split.

Establishment of area code 905 in a split from 416

On October 11, 1993, area code 905 was established in southern Ontario as a split from area code 416. The new code served the Golden Horseshoe region surrounding Toronto, while 416 was retained for the City of Toronto.

Area code 905 introduced as a split from 416

Area code 905 was created in October 1993 as a split from area code 416 to serve the Golden Horseshoe region surrounding Lake Ontario in Southern Ontario, Canada. This split was necessitated by rapid growth and telecommunications demand in the region. Permissive dialing of 416 continued until January 1, 1994.

Mandatory dialing for 416 and 905

Mandatory dialing for area codes 416 and 905 began on March 26, 1994, ending the permissive period and requiring callers to use the correct area code for calls within the region.

Permissive dialing period for 416/905 split ends

Permissive dialing, allowing calls to be completed using either 416 or 905, ended on March 26, 1994, after the 1993 split. After this date, dialing the correct area code became mandatory.

NPA 647 overlay on 416 announced

NPA 647 To Overlay NPA 416 (Southern Ontario)

Area code 647 overlay introduced on 416

Area code 647 was introduced as an overlay to area code 416 on March 5, 2001, creating Canada's first overlay area code and making ten-digit dialing mandatory in Toronto.

NPA 437 overlay on 416/647 announced

NPA 437 to Overlay NPA 416/647 (Toronto, Canada)

NPA 437 overlay on 416/647 announced

NPA 437 to Overlay NPA 416/647 (Toronto, Canada)

NPA 437 overlay on 416/647 announced

NPA 437 to Overlay NPA 416/647 (Toronto, Canada)

Area code 437 overlay introduced on 416/647

Area code 437 was added as a second overlay to the Toronto numbering plan area on March 25, 2013, to address number exhaustion in the 416 and 647 area codes.

NPA 942 overlay on 416/437/647 announced

NPA 942 to Overlay NPA 416/437/647 (Toronto, Ontario)

Area code 942 overlay activated on 416/437/647

Area code 942 was activated on April 26, 2025, as a new overlay to the existing 416, 437, and 647 area codes in Toronto to provide additional numbering resources.