Area Code Lookup
What Area Code Is Markham?
3 area codes serve Markham · Ontario
Markham is served by area codes 289, 365, 742. It is located in Ontario.
Area Codes Serving Markham
Frequently Asked Questions
What area code is Markham?
Markham is served by area codes 289, 365, 742. It is located in Ontario.
Why does Markham have multiple area codes?
As demand for phone numbers increased, NANPA added area codes through splits (dividing the region) or overlays (layering a new code over the same geography). Markham now has 3 area codes — 289 and 365 and 742 — covering the same or overlapping areas.
How do I call Markham from outside the US?
To call Markham from abroad, dial +1 followed by the area code and 7-digit local number (e.g. +1-289-XXX-XXXX). The +1 is the country code for all NANPA countries.