Area code 443: where it is and who calls from it
Area code 443 is in Maryland.
Maryland (Baltimore, Annapolis, Columbia, and all counties and cities which touch the Chesapeake Bay, the Atlantic Ocean, or Delaware, except for St. Mary's County (in 301))
| Where | Maryland |
|---|---|
| Time zone | Eastern Time ยท local time |
| In service since | 1997 |
| Overlay | Yes, with 410, 667 |
| Prefixes assigned | 785 of 792 possible (99%) |
Overlay: 443 covers the same area as 410, 667. Overlay areas use 10-digit dialing, so a seven-digit number alone won't connect, and neighbors can have different area codes.
Where 443 numbers started
Every prefix is assigned to a rate center, the local calling area it was set up in. These are the biggest in 443, with how many prefixes each has.
Plus 19 smaller rate centers.
Who holds 443 numbers
- Mobile carrier 40%
- Local phone company 7%
- Internet / business phone carrier 52%
- Phone company 1%
| Carrier | Type | Prefixes | Share |
|---|---|---|---|
| Windstream (PAETEC) | Internet / business phone carrier | 153 | 19% |
| Verizon Wireless | Mobile carrier | 121 | 15% |
| T-Mobile (including Sprint) | Mobile carrier | 95 | 12% |
| Level 3 (Lumen) | Internet / business phone carrier | 74 | 9% |
| AT&T Mobility | Mobile carrier | 71 | 9% |
| Verizon (local phone) | Local phone company | 55 | 7% |
| MCImetro (Verizon Business) | Internet / business phone carrier | 53 | 7% |
| Teleport Communications America | Internet / business phone carrier | 48 | 6% |
| Core Communications | Internet / business phone carrier | 34 | 4% |
| MetroPCS (T-Mobile) | Mobile carrier | 25 | 3% |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number.
States served: Maryland.
Other area codes in Maryland
Got a call from 443?
An area code tells you where a number was first assigned, not where the caller is. People keep their numbers when they move, and scammers can fake any number. If you weren't expecting the call, let it go to voicemail.
If the call shows a 443 number that matches the first six digits of your own, that's often neighbor spoofing. Use the box above to check the full number.
Area code facts from the NANPA area code database (updated 10/06/2026); prefixes and carriers from NANPA's central office code records (updated 2026-10-10). Place description adapted from Wikipedia, CC BY-SA 4.0.