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Area code 365: Ontario

What is area code 365?

Area code 365 is a Canadian province area code for Ontario, on Eastern Time. It has 706 prefixes in service across 88 exchange areas, the largest being Markham, Hamilton and Brampton. It shares its area with 289, 742 and 905, so local numbers there can start with any of them. Local calls there take 10 digits.

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Area code 365 facts

LocationOntario, Canada
Time zoneEastern Time
Overlays289, 742, 905
Overlay of905
In service sinceMarch 25, 2013
Local calls10 digits; toll calls 1 + 10 digits
CarrierNot shown. An area code is where a number was issued; numbers port between carriers. Check line type

In short: 365 is Ontario (Eastern Time). Format checks here are free and run in your browser; the current carrier and line type need a live lookup. Bulk phone number validator · Pro + Phone plan

Local time in area code 365

 

America/Toronto

Prefixes in service

706 of 792 possible

88 exchange areas

Which cities and towns use area code 365?

The Canadian Numbering Administrator records each prefix against an exchange area, usually named after its main town. These are the 365 exchange areas with the most prefixes in service. 76 smaller ones aren't listed.

Exchange areaPrefixes
Markham51
Hamilton48
Brampton27
Thornhill24
Oshawa23
Ajax-Pickering21
Aurora20
Oakville17
St. Catharines-Thorold15
Newmarket13
Burlington12
Dunnville11

Source: Canadian Numbering Administrator CO code status, file dated 2026-10-16. Each prefix holds up to 10,000 numbers.

How do I dial a 365 number?

NANPA's dialling plan for 365: local calls inside the code take 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.

Local call inside 365365-555-0147
From another US or Canadian area code1-365-555-0147
From outside North America+1 365 555 0147
E.164, for CRMs and SMS tools+13655550147

When did area code 365 start?

Area code 365 went into service on March 25, 2013 as an overlay of 905. Today 365, 289, 742 and 905 cover the same area as an overlay, which is why 10-digit dialling is needed for local calls there.

Tools for 365 numbers

Next step

A 365 number tells you where it was issued, not what it is now.

Mobiles, landlines and VoIP lines share area codes, and numbers move between carriers. A live line-type and carrier lookup on every number in your list says which is which, and that decides which calling and texting rules apply. It's in the phone add-on.

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Area code 365 questions

What province is area code 365?
Area code 365 is in Ontario, Canada. Its largest exchange areas by number of prefixes are Markham, Hamilton, Brampton, Thornhill and Oshawa.
What time zone is area code 365 in?
Eastern Time.
What area codes overlay 365?
289, 742 and 905. An overlay adds a new code to the same area instead of splitting it, so neighbours can have different area codes and local calls need 10 digits.
When did area code 365 start?
Area code 365 went into service on March 25, 2013 as an overlay of 905.
Is a 365 number a cell phone or a landline?
The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
How many phone numbers does area code 365 have?
706 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
Does a valid format mean a 365 number is in service?
No. A format check only says the digits fit the North American Numbering Plan and that 365 is an assigned code. It cannot tell whether the number is connected, who answers it or which carrier serves it today, because numbers are reassigned and ported. A live carrier lookup reports the current carrier and line type, but even that is not proof someone answers.
Can I check a list of 365 numbers for free?
Yes. Paste them in the list tab above or upload a CSV to the bulk phone number validator: format, E.164, country and the numbering-plan line type are free for every row, with no account. Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month).

Other area codes in Ontario

All Ontario area codes on the area code index.

226249289343382416437519548613647683705742753807905942

Sources

Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and exchange areas: Canadian Numbering Administrator CO code status, 2026-10-16. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.

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