Area code 343

343 is an eastern Ontario area code, issued since May 17, 2010. It covers the same ground as 613 and 753: Ottawa, the Ottawa Valley, Kingston, Belleville, Cornwall and the towns around them. Gatineau, across the river, uses Quebec's codes.

• May 17, 2010343 numbers first issued
• 132Exchange areas in the 343 group
• 3Codes sharing the area: 613, 343, 753
• 871Code set aside for the area's next round

Where 343 numbers are issued

343 shares 132 exchange areas with 613 and 753.¹ 131 are in Ontario, from Ottawa and Pembroke to Kingston, Belleville, Brockville and Cornwall. The other is St-Regis, in Quebec, which belongs to the Cornwall region.¹

Ottawa's exchange area appears as Ottawa-Hull in the administrator's list, so lookup sites can show that name for a 343 number. Gatineau and Aylmer are in Quebec's 819, 873 and 468 group.¹

Why 343 came sooner than planned

613 entered the administrator's 72-month relief planning window in November 2006.³ The planning committee recommended a new overlay starting Sept. 18, 2010. On Sept. 10, 2008, the CRTC chose 343 and moved the start four months earlier, to May 17, 2010.^3,4

The CRTC picked 343 because it hadn't been used as a local prefix inside the area or next to it, which it said reduces dialling confusion.⁴ In March 2009 it also told carriers to make sure people knew they wouldn't need to dial 1 for local calls between 613 or 343 and Gatineau's 819.³

Exact dates are NANPA in-service dates. The administrator's history gives years or months.^2,5

753 came on a tighter schedule. A January 2021 forecast moved exhaust up to October 2022 and put the area in a jeopardy condition. The CRTC set 753 for March 26, 2022, six months before that date.⁶

When eastern Ontario needs a fourth code

The administrator's July 2026 forecast gives 613, 343 and 753 until May 2032, 26 months sooner than the January 2026 forecast said.⁷ The area isn't in relief planning yet.⁸ The CRTC set aside 871 for eastern Ontario in May 2025.⁹

Projected exhaust dates from the administrator's status report posted Sept. 29, 2026.⁸

Calls from 343 numbers

Ottawa numbers can look official. The Canada Revenue Agency tells people not to trust the number on call display: get the caller's name and callback number, end the call, and check the number with the agency's verification tool before you call back.¹⁰ The CRTC says callers can display the number of a real person or organization.¹¹

• Don't trust call display. The Canadian Anti-Fraud Centre says never to assume the number on your screen is accurate, for calls or texts.¹²
• Call back on a number you find yourself. If a caller says they're from your bank, a service provider, the police or a government agency, hang up and call the number on your card, your statement or the organization's website.^11,12
• Don't tap links in texts. Forward suspicious texts to 7726 (SPAM), then delete them.^12,13
• Report it. Report fraud to the Canadian Anti-Fraud Centre at 1-888-495-8501 or to your local police, even if you didn't lose money.^11,13
• Cut down on telemarketing. Register your number on the National Do Not Call List and file a complaint about unwanted telemarketing calls.¹¹

What people are saying

We read Ottawa threads on Reddit about 343 numbers. In 2018, some still treated it as second-rate.

• "The 4 years of 10 digit dialing are finally worth it!"

  Commenter on r/ottawa, Dec. 30, 2014¹⁴

  Ten-digit local dialling had been mandatory in 613 since October 2006, eight years before this comment.⁵

• "Got mine from ROGERS. It’s an adjunct code for Ottawa since we are running short on 613."

  Commenter on r/ottawa, Feb. 28, 2018¹⁵

  Right about why it exists. 343 was added because 613 was running out, and it covers all of eastern Ontario, not only Ottawa.^1,4

• "I pretty much boycott 343 numbers. Won't call, won't answer. Get a real number."

  Commenter on r/ottawa, Feb. 19, 2018¹⁵

  A 343 number is as local as a 613 one. Both codes cover the same exchange areas.¹

Claims we checked

• False
  The 343 area code was added in March 2010.

  KrispCall's 343 page gives that month.¹⁶ The CRTC set May 17, 2010 as the start date, and NANPA lists 343 in service from May 17, 2010.^2,4

Questions people ask

How we did this

We counted exchange areas in the Canadian Numbering Administrator's listing dated Oct. 7, 2026, and took the history from the administrator's relief history, its archived 613 relief report, the NANPA database and CRTC decisions 2008-89, 2021-372 and 2025-113. Forecasts come from the administrator's Sept. 29, 2026 status report and July 2026 forecast results. Advice on calls comes only from the CRA, the CRTC, the Canadian Anti-Fraud Centre and the Government of Canada. Reddit quotes are verbatim, with usernames left out. The clock uses fixed offsets and Ontario's 2026 time rules, not your device's settings.

Area codes change slowly, but new codes, forecasts and time rules do move. Each change goes in the update log below.

Update log

• Oct. 7, 2026, 10:19 p.m. ETFirst published. Data checked against the numbering administrator's and NANPA's files dated Oct. 7, 2026.