Area Code 905

About Area Code 905

Area code 905 is a geographic telephone area code assigned to Mississauga, Ontario. It operates in the Eastern time zone and was first introduced in 1993. Split from 416. Golden Horseshoe Ontario. Overlays 289, 365, 742 added.

Within Ontario, area code 905 operates alongside 15 other area codes. The province's 2023 population estimate is 15,996,389. Ontario's capital is Toronto and its largest city is Toronto.

When you receive a call from a 905 number on your Caller ID, the call originated from a phone number assigned to the 905 area code — but be aware that Local Number Portability (in effect since 2003) means the caller could be physically located anywhere in the US or Canada. Area code 905 only confirms where the number was originally assigned.

Where is the 905 area code located?

Area code 905 is assigned to Mississauga, Ontario, in the Eastern time zone. The state of Ontario uses 16 active area codes, and 905 is one of them. Calls placed from the 905 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 905 prefix appears on Caller ID for both landline and wireless calls placed from this region.

The Eastern time zone observes Daylight Saving Time, shifting from UTC-5 to UTC-4 in summer. The local time shown above is always current, so you can quickly check whether it's a reasonable hour to call back.

What cities and counties use the 905 area code?

The 905 area code serves 12 notable cities, listed below in order of population. The largest city in the 905 territory is Mississauga (717,961 residents in Mississauga County).

• Mississauga, ON — 717,961 residents (9.3% of 905 numbers)
• Toronto, ON — 2,794,356 residents (36.1% of 905 numbers)
• Ottawa, ON — 1,017,449 residents (13.1% of 905 numbers)
• Brampton, ON — 656,480 residents (8.5% of 905 numbers)
• Hamilton, ON — 569,353 residents (7.4% of 905 numbers)
• London, ON — 422,324 residents (5.5% of 905 numbers)
• Markham, ON — 338,503 residents (4.4% of 905 numbers)
• Vaughan, ON — 323,103 residents (4.2% of 905 numbers)
• Kitchener, ON — 257,030 residents (3.3% of 905 numbers)
• Windsor, ON — 229,660 residents (3% of 905 numbers)

Phone number format in area code 905

All phone numbers within area code 905 follow the standard North American 10-digit format:(905) NXX-XXXX. The NXX is the central office prefix (also called an "exchange") and XXXX is the subscriber line number. For long-distance calls within the NANP, dial 1 + 905 + NXX + XXXX. From outside North America, dial your country's international access code, then 1 (the NANP country code), then the 10-digit number.

If you need to verify whether a specific 905 number is wireless, landline, or VoIP, you can use our reverse phone lookup tool. Be aware that number portability means the area code no longer guarantees the caller's physical location — only where the number was first assigned.

History of area code 905

Split from 416. Golden Horseshoe Ontario. Overlays 289, 365, 742 added.

The original 86 area codes were assigned by AT&T and Bell Labs in 1947 as part of the North American Numbering Plan. At the time, rotary-dial phones meant codes with lower digits (like 212 for NYC, 213 for LA, 312 for Chicago) were given to the largest cities because they took less time to dial. Today's area code assignments still reflect those early choices, even though touch-tone and cell phones made the original reason obsolete.

Is the 905 area code safe to answer?

Area code 905 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 905 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.