Phone prefixes in Chateauguay, QC

In numbers

In-service prefixes

18

Telephone numbers covered

180,000

Carriers

8

Area codes

3

Provinces and territories

1

First assignment

April 22, 2004

Most recent assignment

June 28, 2023

Chateauguay’s share of its area codes

Within area code 450, Chateauguay accounts for only 10 of 775 prefixes (1.3%): the code is dominated by Granby and spread over 129 rate centres. Within area code 579, Chateauguay accounts for only 7 of 644 prefixes (1.1%): the code is dominated by Granby and spread over 126 rate centres. Within area code 354, Chateauguay accounts for only 1 of 56 prefixes (1.8%): the code is dominated by Valleyfield and spread over 49 rate centres.

Who holds these numbers

Bell Canada holds the largest share at 5 prefixes, 27.8% of the total, ahead of 7 other carriers. Code by code: in 450, Bell Canada leads with 4 of 10 prefixes ahead of 3 others; in 579, Fibernetics Corporation leads with 2 of 7 prefixes ahead of 5 others; Iristel Inc. is the only holder in 354. 1 carrier holds prefixes in every one of Chateauguay’s 3 area codes, while 6 appear in just one.

Wireless and wireline

1 of Chateauguay’s 18 prefixes (5.6%) are held by carriers whose registered name marks a wireless business: Fido Solutions Inc. Wireline prefixes still outnumber them, carried by Bell Canada, Videotron Ltd, Iristel Inc and Fibernetics Corporation. 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

Chateauguay’s dated assignments run from 2004 to 2023. The busiest period was 2010–2014, when 5 prefixes went to 4 carriers. 4 prefixes (22%) carry no date in the register: these are the historic pre-1999 assignments, the wireline bedrock of the rate centre. Since 2020 another 3 prefixes have been added, so the rate centre is still growing.

Chateauguay’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 Videotron Ltd. in 2004. The most recent arrivals are Fibernetics Corporation (2021), TELUS Quebec (2019) and Bell Canada (2016), a sign that new carriers are still asking for numbers in Chateauguay.

Chateauguay has only 18 prefixes, or 180,000 numbers: a small rate centre, where the arrival of a single new carrier visibly changes the landscape.

No single carrier dominates Chateauguay: the leader, Bell Canada, holds only 27.8% of the prefixes against 7 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: 21.4% of the dated prefixes go back to the last ten years, the most active period being 2010–2014. The rate centre is growing at a regular rather than explosive pace.

The register also shows 1 prefix assigned but not yet in service in Chateauguay (Cogeco Connexion Inc): numbers that will start showing up on call displays in the coming months.

4 undated in the register.

Dialling a Chateauguay number

Chateauguay is served by 3 overlaid area codes (450, 579 and 354). A 354 number is no more “out of town” than a 450 one; from abroad, dial +1 and the full ten digits.

The numbering neighbourhood

Chateauguay shares area codes 450, 579 and 354 with at least 20 other rate centres, including Granby, Joliette, St-Jerome, St-Hyacinthe, Longueuil, Ste-Therese, St-Lambert and Sorel. The largest of them, Granby, holds 52 prefixes in 354, 450 and 579; the smallest on the list, St-Vincent-de-Paul, has just 17.

What a Chateauguay number tells you

A number attached to Chateauguay tells you that its prefix was issued to a carrier for this rate centre in Quebec, 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 8 carriers present here or to a VoIP service usable anywhere. Nor does it tell you who is calling: caller ID can be spoofed, and a Quebec area code is easy to borrow to look local.

Reading a register entry for Chateauguay: code 450-691 is recorded for Bell Canada, so every 450-691-XXXX number (10,000 possible) descends from that assignment. “Chateauguay, Quebec” there names a rate centre, not a municipality, and several area codes overlay it.

Every Chateauguay prefix

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

Had a call from a Chateauguay 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 18 in-service prefixes, grouped by rate centre.

Elsewhere in Quebec