The 443 area code covers the same area as 410, including Baltimore, Towson and 90 more places in Maryland.
Area code 443 is in Maryland, on Eastern Time. In the 443 area, phone numbers are given out most in Baltimore County, then the City of Baltimore and Anne Arundel County. It has been in service since June 1, 1997. 410 and 667 cover the same area, so two neighbours can have different area codes.
- Where
- 8 counties in Maryland, mostly Baltimore County, City of Baltimore and Anne Arundel County
- Time zone
- Eastern Time
- In service since
- June 1, 1997
- Shares its area with
- 410 (since 1991) and 667 (since 2012)
- Prefixes in use
- 785
- How to dial
- Local calls need all 10 digits: 443-555-0142.
Find out who called you from a 443 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (443) number is on today, use our free carrier lookup.
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Baltimore holds 24% of the phone prefixes in area code 443.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 785 prefixes in use shows where 443 numbers are actually given out.
- Baltimore185 prefixes, 24%
- Annapolis39 prefixes, 5%
- Towson33 prefixes, 4%
- Columbia31 prefixes, 4%
- Glen Burnie26 prefixes, 3%
- Catonsville22 prefixes, 3%
- Pikesville21 prefixes, 3%
- Salisbury20 prefixes, 3%
Also served: Pikesville, Severna Park, Ellicott City and Cockeysville and 80 smaller places.
PAETEC (Windstream) holds the most phone number prefixes in area code 443: 153 of 785.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 785 prefixes in use in 443 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| PAETEC (Windstream)Windstream's business phone network | 153 | 19% |
| T-MobileMobile network | 95 | 12% |
| Level 3 (Lumen)Lumen's business and wholesale network | 74 | 9% |
| AT&T MobilityMobile network | 71 | 9% |
| Teleport (AT&T)AT&T's business phone network | 48 | 6% |
| Core Communications | 34 | 4% |
| 17 other carriers | 310 | 39% |
89% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
443 has been overlaid once since 1997.
1997
443 starts on June 1, 1997, as an overlay on 410: new numbers on the same ground.
2012
On March 24, 2012, 667 is added on top of 443, so new numbers here can get either code.
A 443 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 443 are 302, 202 and 703.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
These are the questions people ask most about area code 443.
Where is area code 443?
443 covers Baltimore, Towson, Annapolis and Catonsville and 88 more places in Maryland. In the 443 area, phone numbers are given out most in Baltimore County, then the City of Baltimore and Anne Arundel County.
What state is area code 443 in?
Maryland. 443 is a Maryland area code on Eastern Time.
What cities use area code 443?
The places holding the most 443 prefixes are Baltimore, Towson, Annapolis, Catonsville, Glen Burnie, Salisbury, Elkridge and Columbia, out of 92 places in all. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 443?
No single phone company owns 443. NANPA's records show PAETEC (Windstream) holds the most 443 prefixes, 153 of 785, followed by T-Mobile and Level 3 (Lumen). Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 443 in?
443 is on Eastern Time.
When did area code 443 start?
443 went into service on June 1, 1997, as an overlay on 410: new numbers for the same area.
Is 443 the same area as 410 and 667?
Yes. 410 (since 1991) and 667 (since 2012) cover the same ground as 443. Nobody's number changed when they were added; new lines simply get whichever code has numbers left, so two neighbours can have different codes.
How do I dial a 443 number?
Local calls need all 10 digits: 443-555-0142.
Is 443 a toll-free number?
No. 443 is a regular area code for Baltimore and Towson in Maryland, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 443?
The closest are 302 (Wilmington, Delaware), 202/771 (Washington, D.C.), 703/571 (Washington, D.C. suburbs, Virginia) and 856 (Camden, New Jersey), measured between the centres of each area.
Who called me from a 443 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 443 a scam?
443 is a real Maryland area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.