Phone prefixes in St-Thomas-d'Aquin, QC

In numbers

In-service prefixes

8

Telephone numbers covered

80,000

Carriers

7

Area codes

3

Provinces and territories

1

First assignment

September 9, 2002

Most recent assignment

March 26, 2025

St-Thomas-d'Aquin’s share of its area codes

Within area code 450, St-Thomas-d'Aquin accounts for only 5 of 775 prefixes (0.6%): the code is dominated by Granby and spread over 129 rate centres. Within area code 579, St-Thomas-d'Aquin accounts for only 2 of 644 prefixes (0.3%): the code is dominated by Granby and spread over 126 rate centres. Within area code 354, St-Thomas-d'Aquin 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

Telebec Ltee. holds the largest share at 2 prefixes, 25.0% of the total, ahead of 6 other carriers. Code by code: in 450, Telebec Ltee. leads with 1 of 5 prefixes ahead of 4 others; in 579, Telebec Ltee. leads with 1 of 2 prefixes ahead of 1 others; Cogeco Connexion Inc. is the only holder in 354. No carrier holds prefixes in every one of St-Thomas-d'Aquin’s 3 area codes, while 6 appear in just one.

Wireless and wireline

None of St-Thomas-d'Aquin’s holders carries a mobility brand in its registered name: all 8 prefixes belong to wireline or wholesale carriers, among them Telebec Ltee, 9164-3122 Quebec inc, Cogeco Connexion Inc and Cooptel. A call showing a St-Thomas-d'Aquin number therefore nominally comes from a landline, cable or VoIP platform rather than a locally assigned cellphone.

How the allocation was built up

St-Thomas-d'Aquin’s dated assignments run from 2002 to 2025. The busiest period was 2005–2009, when 2 prefixes went to 2 carriers. 1 prefixes (13%) carry no date in the register: these are the historic pre-1999 assignments, the wireline bedrock of the rate centre. Since 2020 another 2 prefixes have been added, so the rate centre is still growing.

St-Thomas-d'Aquin’s oldest prefixes, the ones the register leaves undated, belong to Telebec Ltee: this carrier made up the landscape before competition arrived. The first dated assignment went to Groupe Maskatel Quebec LP in 2002. The most recent arrivals are Cogeco Connexion Inc. (2025), Cooptel (2021) and Telebec Ltee. (2018), a sign that new carriers are still asking for numbers in St-Thomas-d'Aquin.

St-Thomas-d'Aquin has just 8 prefixes (80,000 numbers): a very small rate centre, typical of a village or rural area served by a single switching office.

No single carrier dominates St-Thomas-d'Aquin: the leader, Telebec Ltee., holds only 25.0% of the prefixes against 6 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: 28.6% 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.

1 undated in the register.

Dialling a St-Thomas-d'Aquin number

St-Thomas-d'Aquin 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-Thomas-d'Aquin 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, Beloeil, has just 17.

What a St-Thomas-d'Aquin number tells you

A number attached to St-Thomas-d'Aquin tells you that its prefix was issued to a carrier for this rate centre in Quebec, most often Telebec Ltee.. It does not tell you where the handset is today: a subscriber may have ported the number to any of the 7 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-Thomas-d'Aquin: code 450-796 is recorded for Telebec Ltee., so every 450-796-XXXX number (10,000 possible) descends from that assignment. “St-Thomas-d'Aquin, Quebec” there names a rate centre, not a municipality, and several area codes overlay it.

Every St-Thomas-d'Aquin prefix

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

Allocated prefixes

All 8 in-service prefixes, grouped by rate centre.

Elsewhere in Quebec