Area Code 403

About Area Code 403

Area code 403 is a geographic telephone area code assigned to Calgary, Alberta. It operates in the Mountain time zone and was first introduced in 1947. Original Canadian code. Southern Alberta. Overlays 587, 825, 368 added.

Within Alberta, area code 403 operates alongside 4 other area codes. The province's 2023 population estimate is 4,715,510. Alberta's capital is Edmonton and its largest city is Calgary.

When you receive a call from a 403 number on your Caller ID, the call originated from a phone number assigned to the 403 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 403 only confirms where the number was originally assigned.

Where is the 403 area code located?

Area code 403 is assigned to Calgary, Alberta, in the Mountain time zone. The state of Alberta uses 5 active area codes, and 403 is one of them. Calls placed from the 403 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 403 prefix appears on Caller ID for both landline and wireless calls placed from this region.

The Mountain time zone observes Daylight Saving Time, shifting from UTC-7 to UTC-6 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 403 area code?

The 403 area code serves 10 notable cities, listed below in order of population. The largest city in the 403 territory is Calgary (1,306,784 residents in Calgary County).

• Calgary, AB — 1,306,784 residents (45.6% of 403 numbers)
• Edmonton, AB — 1,010,899 residents (35.3% of 403 numbers)
• Red Deer, AB — 103,588 residents (3.6% of 403 numbers)
• Lethbridge, AB — 106,550 residents (3.7% of 403 numbers)
• St. Albert, AB — 69,217 residents (2.4% of 403 numbers)
• Medicine Hat, AB — 63,280 residents (2.2% of 403 numbers)
• Grande Prairie, AB — 64,718 residents (2.3% of 403 numbers)
• Airdrie, AB — 70,564 residents (2.5% of 403 numbers)
• Spruce Grove, AB — 37,379 residents (1.3% of 403 numbers)
• Lloydminster, AB — 31,582 residents (1.1% of 403 numbers)

Phone number format in area code 403

All phone numbers within area code 403 follow the standard North American 10-digit format:(403) 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 + 403 + 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 403 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 403

Original Canadian code. Southern Alberta. Overlays 587, 825, 368 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 403 area code safe to answer?

Area code 403 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 403 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.