Phone prefixes in Ste-Rosalie, QC

In numbers

In-service prefixes

3

Telephone numbers covered

30,000

Carriers

3

Area codes

3

Provinces and territories

1

First assignment

October 24, 2012

Most recent assignment

August 26, 2025

Ste-Rosalie’s share of its area codes

Within area code 354, Ste-Rosalie accounts for only 1 of 56 prefixes (1.8%): the code is dominated by Valleyfield and spread over 49 rate centres. Within area code 450, Ste-Rosalie accounts for only 1 of 775 prefixes (0.1%): the code is dominated by Granby and spread over 129 rate centres. Within area code 579, Ste-Rosalie accounts for only 1 of 644 prefixes (0.2%): the code is dominated by Granby and spread over 126 rate centres.

Who holds these numbers

Cogeco Connexion Inc. holds the largest share at 1 prefixes, 33.3% of the total, ahead of 2 other carriers. Code by code: Cogeco Connexion Inc. is the only holder in 354; Telephone Guevremont Inc. is the only holder in 450; TELUS Quebec is the only holder in 579. No carrier holds prefixes in every one of Ste-Rosalie’s 3 area codes, while 3 appear in just one.

Wireless and wireline

None of Ste-Rosalie’s holders carries a mobility brand in its registered name: all 3 prefixes belong to wireline or wholesale carriers, among them Cogeco Connexion Inc, TELUS Quebec and Telephone Guevremont Inc. A call showing a Ste-Rosalie number therefore nominally comes from a landline, cable or VoIP platform rather than a locally assigned cellphone.

How the allocation was built up

Ste-Rosalie’s dated assignments run from 2012 to 2025. The busiest period was 2010–2014, when 1 prefixes went to 1 carrier. 1 prefixes (33%) carry no date in the register: these are the historic pre-1999 assignments, the wireline bedrock of the rate centre. Since 2020 another 1 prefixes have been added, so the rate centre is still growing.

Ste-Rosalie’s oldest prefixes, the ones the register leaves undated, belong to Telephone Guevremont Inc: this carrier made up the landscape before competition arrived. The first dated assignment went to TELUS Quebec in 2012. The most recent arrivals are Cogeco Connexion Inc. (2025) and TELUS Quebec (2012), a sign that new carriers are still asking for numbers in Ste-Rosalie.

Ste-Rosalie has just 3 prefixes (30,000 numbers): a very small rate centre, typical of a village or rural area served by a single switching office.

No single carrier dominates Ste-Rosalie: the leader, Cogeco Connexion Inc., holds only 33.3% of the prefixes against 2 competitors, a sign of a highly fragmented market where cable companies, mobility brands and VoIP providers weigh as much as the incumbent.

Growth is recent: 50.0% of the dated prefixes were assigned in the last ten years, peaking in 2010–2014. Ste-Rosalie is among the rate centres where demand for numbers is still rising quickly.

1 undated in the register.

Dialling a Ste-Rosalie number

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

The numbering neighbourhood

Ste-Rosalie shares area codes 354, 450 and 579 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, Beloeil, has just 17.

What a Ste-Rosalie number tells you

A number attached to Ste-Rosalie tells you that its prefix was issued to a carrier for this rate centre in Quebec, most often Cogeco Connexion Inc.. It does not tell you where the handset is today: a subscriber may have ported the number to any of the 3 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 Ste-Rosalie: code 354-241 is recorded for Cogeco Connexion Inc., so every 354-241-XXXX number (10,000 possible) descends from that assignment. “Ste-Rosalie, Quebec” there names a rate centre, not a municipality, and several area codes overlay it.

Every Ste-Rosalie prefix

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

Allocated prefixes

All 3 in-service prefixes, grouped by rate centre.

Elsewhere in Quebec