Area code

ONTARIO

Canada geographic area code, in service since 2016-06-04. Part of the 226/382/519/548 overlay complex — ten-digit dialing required.

Split from 226. Overlaid with 226, 382, 519 .

Statusin service

Introduced2016-06-04

JurisdictionONTARIO, CANADA

Local dialing10D

Time zoneEastern

Last verified2026-09-17

Area codes serve rate-center geographies, not municipal boundaries. “ONTARIO” identifies the jurisdiction, not an exact city footprint.

Change history

Recorded events for this NPA

2014-11-03 NPA 548 to Overlay NPA 226/519 (Southwestern Ontario, Canada) overlay
2016-06-04Area code 548 entered service (created from 226).

Primary documents

NANPA planning letters for area code 548
Date	Document	Subject
2014-11-03	PL-472 ↗	NPA 548 to Overlay NPA 226/519 (Southwestern Ontario, Canada)
2014-04-21	PL-467 ↗	NPA 548 to Overlay NPA 226/519 (Southwestern Ontario, Canada)