Toronto Area Codes: 416, 647, 437 and 942 Explained

Toronto has four telephone area codes: 416, 647, 437, and 942. All four cover the same territory, the City of Toronto, which the Canadian Numbering Administrator (CNA) treats as a single exchange area named Toronto. Area code 416 dates from 1947, 647 was added in March 2001 as the first overlay in Canada, 437 followed on March 25, 2013, and 942 began on April 26, 2025. A number’s area code reflects when it was issued, not which part of the city its owner lives in.

The older article on this site about postal codes and area codes (linked at the end) explains how Canadian postal codes work. This article concentrates on the telephone side: how the area codes came about, why Toronto kept adding them, and what the regulator’s documents say about dialing.

Quick answers

416 is the original Toronto area code and today covers the whole city, not only downtown.
647, 437, and 942 are overlays on that same territory, so a downtown office can have any of the four.
The surrounding region uses different codes: 905, 289, and 365, which the CNA’s relief history describes as serving the areas around Toronto.
Local calls within the Toronto area are dialed with all ten digits.

How the area codes were added

The table below follows the CNA’s published history of area code relief in Canada and the CRTC and CNA documents cited in it.

Year	Event
1947	Area code 416 is among the first area codes put into service in the North American numbering area. The history records an AT&T assignment of 86 codes, nine of them in Canada.
1953	Area code 519 is created for part of Ontario, split from parts of 416 and 613. This is the first reduction of 416’s territory.
1962	The 416 and 705 boundary is modified and the Peterborough area moves into 705.
1993	Area code 905 is split from 416. Toronto keeps 416 and the areas surrounding it receive 905.
March 2001	Area code 647 is introduced as an overlay on 416. The history notes mandatory ten-digit local dialing and calls it the first Canadian overlay.
March 25, 2013	Area code 437 is introduced as an overlay on 416 and 647, under Telecom Decision CRTC 2011-436 of July 22, 2011.
April 26, 2025	Area code 942 is introduced as an overlay on 416, 437, and 647, under Telecom Decision CRTC 2023-135 of May 10, 2023.

Before 1993, then, a 416 number could belong to a town well outside today’s city limits. Since the 905 split the code has pointed to Toronto itself.

Why an overlay and not a split

Earlier relief used splits, which divide a territory and force one half to change its code. In 2011 the relief planning committee for 416 and 647 explained why that option was not examined in detail: the area consists of a single exchange area, Toronto, and ten-digit local dialing was already in place. A distributed overlay keeps the existing boundaries and the existing numbers, and adds a new code over the same ground. The committee also noted that the overlay would cost less for some carriers than the alternatives. The CRTC accepted this plan in Decision 2011-436, and the 437 code went live on March 25, 2013, the same day as a relief for the 905 region.

Why Toronto ran short of numbers

Each area code holds a limited pool of seven-digit numbers, and carriers receive them in blocks. The CNA publishes forecasts of when a code will run out. In 2010 its forecast put the exhaustion of 416 and 647 at July 2015; by early 2011 the projection had moved to May 2014, which led to the 437 overlay. The 942 decision followed the same pattern. According to the CRTC’s summary of Decision 2023-135, the CNA advised in March 2019 that the 416, 437, and 647 complex was projected to run out by January 2024, and a later report moved the date to April 2026. A shortage of numbers is therefore the stated reason for each new code, and the population of the city does not enter the calculation directly.

Ten-digit dialing

Ten-digit dialing has been the rule in Toronto since the 647 overlay of 2001. The CNA’s history lists mandatory ten-digit local dialing as part of that change, and the 2011 planning document confirms that it was mandatory for local calls within 416 and 647. The CNA’s planning letter for the 942 overlay sets the pattern in writing: all local calls, including extended area service calls, originating within the 416, 437, 647, and 942 area must be dialed with ten digits, area code plus seven-digit number. Toll and alternately billed calls keep their own prefix digits followed by ten digits. Seven-digit dialing, as many older phone numbers were written, does not work for local calls in Toronto.

What the “1” in front means

People often search for “1 416” or “+1 416”. The 1 is the country code of the North American Numbering Plan, which Canada, the United States, and a number of Caribbean countries share. A full international Toronto number is therefore +1, then the three-digit area code, then seven digits. In Canada the CNA administers numbering under CRTC direction, while the North American Numbering Plan Administrator assigns the area codes themselves. The planning letter for 942 records that the code was assigned by that administrator.

What an overlay means for callers

With four codes on one territory, nobody can tell a caller’s neighborhood from the first three digits. A 416 number may have been issued decades ago, while a 942 number was issued after April 2025. The overlay does not move anyone’s number, and it does not turn local calls into long-distance calls. For businesses with phone systems that block long-distance dialing, each new code has to be entered as local. The CNA and the telephone carriers publish the technical notices for such changes, so a business owner should check the CNA website and the carrier for current instructions.

Frequently asked questions

What area codes does Toronto have?

Toronto has 416, 647, 437, and 942. All four apply across the whole city, which makes up one exchange area. The nearby suburbs use 905, 289, and 365.

Is 416 only for downtown Toronto?

No. Since the 905 split in 1993, 416 has covered all of Toronto. Before that split it also covered towns that now belong to the 905 region, and an earlier split in 1953 and a boundary change in 1962 took further territory out of it.

Do all calls in Toronto need ten digits?

Local calls in the 416, 437, 647, and 942 area are dialed with ten digits, according to the CNA planning letter for the 942 overlay. Calls to a 905 number from Toronto were also treated as local ten-digit calls in the 2011 planning document.

When did Toronto get its fourth area code?

The 942 code took effect on April 26, 2025, under CRTC Telecom Decision 2023-135. It joined 416, 647, and 437 as an overlay, and existing numbers did not change.

Last verified: October 2026

Sources

Canadian Numbering Administrator, Canadian Geographic Area Code Relief History
Canadian Numbering Administrator, Planning Letter PL-613, “NPA 942 to Overlay NPA 416/437/647 (Toronto, Ontario),” May 11, 2023, published by the North American Numbering Plan Administrator
NPA 416/647 Relief Planning Committee, Planning Document, May 16, 2011 (CNA relief archive)
CRTC, Telecom Decision 2011-436 and Telecom Decision 2023-135
North American Numbering Plan Administrator, “About NANPA”

Cite this page

APA: History of Toronto. (2026, October 23). Toronto Area Codes 416, 647, 437 and 942: History and Dialing. https://historyoftoronto.ca/blog/area-codes-416-647-437-942

MLA: “Toronto Area Codes 416, 647, 437 and 942: History and Dialing.” History of Toronto, 23 Oct. 2026, https://historyoftoronto.ca/blog/area-codes-416-647-437-942. Accessed .

Chicago: History of Toronto. “Toronto Area Codes 416, 647, 437 and 942: History and Dialing.” Last modified October 23, 2026. https://historyoftoronto.ca/blog/area-codes-416-647-437-942.

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