Phone prefixes in St-Hyacinthe, QC

In numbers

In-service prefixes

42

Telephone numbers covered

420,000

Carriers

17

Area codes

3

Provinces and territories

1

First assignment

April 19, 2000

Most recent assignment

March 26, 2025

St-Hyacinthe’s share of its area codes

Within area code 450, St-Hyacinthe accounts for only 25 of 775 prefixes (3.2%): the code is dominated by Granby and spread over 129 rate centres. Within area code 579, St-Hyacinthe accounts for only 16 of 644 prefixes (2.5%): the code is dominated by Granby and spread over 126 rate centres. Within area code 354, St-Hyacinthe 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 8 prefixes, 19.0% of the total, ahead of 16 other carriers. Code by code: in 450, Bell Canada leads with 7 of 25 prefixes ahead of 10 others; in 579, TELUS Quebec leads with 3 of 16 prefixes ahead of 10 others; Cogeco Connexion Inc. is the only holder in 354. No carrier holds prefixes in every one of St-Hyacinthe’s 3 area codes, while 11 appear in just one.

Wireless and wireline

11 of St-Hyacinthe’s 42 prefixes (26.2%) are held by carriers whose registered name marks a wireless business: TELUS Mobility, Bell Mobility, Rogers Communications Canada Inc. (Wireless) and Fido Solutions Inc. Wireline prefixes still outnumber them, carried by Bell Canada, TELUS Quebec, Videotron Ltd and Groupe Maskatel Quebec LP. 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

St-Hyacinthe’s dated assignments run from 2000 to 2025. The busiest period was 2000–2004, when 9 prefixes went to 6 carriers. 11 prefixes (26%) 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.

St-Hyacinthe’s oldest prefixes, the ones the register leaves undated, belong to Bell Canada, Groupe Maskatel Quebec LP and Fido Solutions Inc: 4 carriers made up the landscape before competition arrived. The first dated assignment went to TELUS Mobility in 2000. The most recent arrivals are Cogeco Connexion Inc. (2025), Cooptel (2022) and Fibernetics Corporation (2021), a sign that new carriers are still asking for numbers in St-Hyacinthe.

St-Hyacinthe’s 42 prefixes provide 420,000 numbers, which corresponds to a mid-sized city or a well-established suburb that every major carrier wants a slice of.

No single carrier dominates St-Hyacinthe: the leader, Bell Canada, holds only 19.0% of the prefixes against 16 competitors, a sign of a highly fragmented market where cable companies, mobility brands and VoIP providers weigh as much as the incumbent.

Allocation is mature: only 19.4% of the dated prefixes are less than ten years old, most having been handed out in 2000–2004, and 11 prefixes go back to the undated monopoly era. New St-Hyacinthe numbers mostly come out of blocks that were assigned long ago.

11 undated in the register.

Dialling a St-Hyacinthe number

St-Hyacinthe 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

St-Hyacinthe shares area codes 450, 579 and 354 with at least 20 other rate centres, including Granby, Joliette, St-Jerome, Longueuil, Ste-Therese, St-Lambert, Sorel and Pont-Viau. 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 St-Hyacinthe number tells you

A number attached to St-Hyacinthe 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 17 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 St-Hyacinthe: code 450-223 is recorded for Bell Canada, so every 450-223-XXXX number (10,000 possible) descends from that assignment. “St-Hyacinthe, Quebec” there names a rate centre, not a municipality, and several area codes overlay it.

Every St-Hyacinthe prefix

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

Had a call from a St-Hyacinthe 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 42 in-service prefixes, grouped by rate centre.

Elsewhere in Quebec