Area Code 443

About Area Code 443

Area code 443 is a geographic telephone area code assigned to Baltimore, Maryland. It operates in the Eastern time zone and was first introduced in 2000. Overlay for 410. Eastern Maryland.

Within Maryland, area code 443 shares numbering capacity with 4 other area codes. The state's 6,180,253-person population (2023 Census Bureau estimate) is served by a combined 5 active codes, with 443 primarily responsible for the Baltimore region. Maryland's state capital is Annapolis, and its largest city is Baltimore.

When you receive a call from a 443 number on your Caller ID, the call originated from a phone number assigned to the 443 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 443 only confirms where the number was originally assigned.

Where is the 443 area code located?

Area code 443 is assigned to Baltimore, Maryland, in the Eastern time zone. The state of Maryland uses 5 active area codes, and 443 is one of them. Calls placed from the 443 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 443 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 443 area code?

The 443 area code serves 10 notable cities, listed below in order of population. The largest city in the 443 territory is Baltimore (565,239 residents in Unknown County).

• Baltimore, MD — 565,239 residents (44.2% of 443 numbers)
• Columbia, MD — 104,251 residents (8.1% of 443 numbers)
• Germantown, MD — 91,765 residents (7.2% of 443 numbers)
• Silver Spring, MD — 81,816 residents (6.4% of 443 numbers)
• Waldorf, MD — 81,410 residents (6.4% of 443 numbers)
• Glen Burnie, MD — 69,260 residents (5.4% of 443 numbers)
• Ellicott City, MD — 75,947 residents (5.9% of 443 numbers)
• Frederick, MD — 79,858 residents (6.2% of 443 numbers)
• Dundalk, MD — 63,057 residents (4.9% of 443 numbers)
• Rockville, MD — 67,117 residents (5.2% of 443 numbers)

Phone number format in area code 443

All phone numbers within area code 443 follow the standard North American 10-digit format:(443) 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 + 443 + 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 443 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 443

Overlay for 410. Eastern Maryland.

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 443 area code safe to answer?

Area code 443 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 443 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.