Area Code 548

About Area Code 548

Area code 548 is a geographic telephone area code assigned to London, Ontario. It operates in the Eastern time zone and was first introduced in 2015. Overlay for 519/226. Southwestern Ontario.

Within Ontario, area code 548 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 548 number on your Caller ID, the call originated from a phone number assigned to the 548 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 548 only confirms where the number was originally assigned.

Where is the 548 area code located?

Area code 548 is assigned to London, Ontario, in the Eastern time zone. The state of Ontario uses 16 active area codes, and 548 is one of them. Calls placed from the 548 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 548 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 548 area code?

The 548 area code serves 11 notable cities, listed below in order of population. The largest city in the 548 territory is London (422,324 residents in London County).

• London, ON — 422,324 residents (5.6% of 548 numbers)
• Toronto, ON — 2,794,356 residents (37.1% of 548 numbers)
• Ottawa, ON — 1,017,449 residents (13.5% of 548 numbers)
• Mississauga, ON — 717,961 residents (9.5% of 548 numbers)
• Brampton, ON — 656,480 residents (8.7% of 548 numbers)
• Hamilton, ON — 569,353 residents (7.6% of 548 numbers)
• Markham, ON — 338,503 residents (4.5% of 548 numbers)
• Vaughan, ON — 323,103 residents (4.3% of 548 numbers)
• Kitchener, ON — 257,030 residents (3.4% of 548 numbers)
• Windsor, ON — 229,660 residents (3.1% of 548 numbers)

Phone number format in area code 548

All phone numbers within area code 548 follow the standard North American 10-digit format:(548) 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 + 548 + 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 548 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 548

Overlay for 519/226. Southwestern Ontario.

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 548 area code safe to answer?

Area code 548 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 548 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.