Phone prefixes in Clarkson, ON

In numbers

In-service prefixes

26

Telephone numbers covered

260,000

Carriers

14

Area codes

4

Provinces and territories

1

First assignment

March 28, 2003

Most recent assignment

June 24, 2024

Clarkson’s share of its area codes

Within area code 289, Clarkson accounts for only 11 of 772 prefixes (1.4%): the code is dominated by Hamilton and spread over 87 rate centres. Within area code 905, Clarkson accounts for only 8 of 773 prefixes (1.0%): the code is dominated by Hamilton and spread over 94 rate centres. Within area code 365, Clarkson accounts for only 5 of 706 prefixes (0.7%): the code is dominated by Markham and spread over 88 rate centres. Within area code 742, Clarkson accounts for only 2 of 149 prefixes (1.3%): the code is dominated by Brampton and spread over 68 rate centres.

Who holds these numbers

Bell Canada holds the largest share at 5 prefixes, 19.2% of the total, ahead of 13 other carriers. Code by code: in 289, TELUS Integrated Communications leads with 3 of 11 prefixes ahead of 7 others; in 905, Bell Canada leads with 5 of 8 prefixes ahead of 1 others; in 365, Fibernetics Corporation leads with 3 of 5 prefixes ahead of 2 others; in 742, Beanfield Technologies Inc. leads with 1 of 2 prefixes ahead of 1 others. No carrier holds prefixes in every one of Clarkson’s 4 area codes, while 13 appear in just one.

Wireless and wireline

1 of Clarkson’s 26 prefixes (3.8%) are held by carriers whose registered name marks a wireless business: Fido Solutions Inc. Wireline prefixes still outnumber them, carried by Bell Canada, Fibernetics Corporation, Rogers Communications Canada Inc. (Cable) and TELUS Integrated Communications. This is a sort by name, not a licence lookup, and a mobile prefix may have been ported to another network since.

How the allocation was built up

Clarkson’s dated assignments run from 2003 to 2024. The busiest period was 2005–2009, when 7 prefixes went to 6 carriers. 4 prefixes (15%) carry no date in the register: these are the historic pre-1999 assignments, the wireline bedrock of the rate centre. Since 2020 another 6 prefixes have been added, so the rate centre is still growing.

Clarkson’s oldest prefixes, the ones the register leaves undated, belong to Bell Canada: this carrier made up the landscape before competition arrived. The first dated assignment went to Bell Canada in 2003. The most recent arrivals are FGLTEL Inc. (2022), Beanfield Technologies Inc. (2021) and TekSavvy Solutions Inc (2020), a sign that new carriers are still asking for numbers in Clarkson.

Clarkson has only 26 prefixes, or 260,000 numbers: a small rate centre, where the arrival of a single new carrier visibly changes the landscape.

No single carrier dominates Clarkson: the leader, Bell Canada, holds only 19.2% of the prefixes against 13 competitors, a sign of a highly fragmented market where cable companies, mobility brands and VoIP providers weigh as much as the incumbent.

Demand remains steady: 27.3% of the dated prefixes go back to the last ten years, the most active period being 2005–2009. The rate centre is growing at a regular rather than explosive pace.

4 undated in the register.

Dialling a Clarkson number

Clarkson is served by 4 overlaid area codes (289, 905, 365 and 742). A 742 number is no more “out of town” than a 289 one; from abroad, dial +1 and the full ten digits.

The numbering neighbourhood

Clarkson shares area codes 289, 905, 365 and 742 with at least 20 other rate centres, including Hamilton, Brampton, Oshawa, St. Catharines-Thorold, Oakville, Markham, Ajax-Pickering and Cooksville. The largest of them, Hamilton, holds 222 prefixes in 289, 365, 742 and 905; the smallest on the list, Dunnville, has just 28.

What a Clarkson number tells you

A number attached to Clarkson tells you that its prefix was issued to a carrier for this rate centre in Ontario, most often Bell Canada. It does not tell you where the handset is today: a subscriber may have ported the number to any of the 14 carriers present here or to a VoIP service usable anywhere. Nor does it tell you who is calling: caller ID can be spoofed, and an Ontario area code is easy to borrow to look local.

Reading a register entry for Clarkson: code 905-403 is recorded for Bell Canada, so every 905-403-XXXX number (10,000 possible) descends from that assignment. “Clarkson, Ontario” there names a rate centre, not a municipality, and several area codes overlay it.

Every Clarkson prefix

Each row is an in-service central-office code recorded for Clarkson, with its original holder and year of assignment.

What people check and report about Clarkson numbers

Searches typed into this site's lookup form since July 28, 2026, plus the verdicts and moderated reports visitors left. A search usually follows a missed call.

Had a call from a Clarkson number?

No clear pattern in reports on these numbers yet. If a call worried you:

1. Call back on a number you trust

   If a caller says they are your bank, the Canada Revenue Agency, a courier or your phone company, hang up and call the organization on the number from its website or your statement, never the number that called you. Caller ID can be faked.

2. Report the fraud

   Report the call or text to the Canadian Anti-Fraud Centre online or at 1-888-495-8501. If you lost money or gave out personal details, tell your bank first, then your local police.

   Report to the Canadian Anti-Fraud Centre ↗

3. Register on the National Do Not Call List

   Registering a landline or mobile on the National DNCL is free. Registered charities, political parties, newspapers and companies you already do business with may still call.

   National Do Not Call List ↗Who can still call you ↗

4. Forward suspicious texts to 7726

   Forward a scam or spam text to 7726 (SPAM on the keypad). It's free, and your carrier uses it to block the sender. Don't tap links or reply.

   Get Cyber Safe: forwarding to 7726 ↗

Allocated prefixes

All 26 in-service prefixes, grouped by rate centre.

Elsewhere in Ontario