Area codes · +1
Area code 443
Area code 443 is centred on Baltimore, Maryland. We hold 7,726 allocated blocks for it across 81 rate centres, split 48% mobile, 40% landline and 12% VoIP.
The other area codes laid over 443
Area code 443 does not have Baltimore to itself. 2 other codes — 410, 667 — serve the same rate centres, laid over the same ground rather than dividing it. That is an overlay: a new code added when the old one ran out of numbers, covering the same streets. Two neighbours can hold different area codes, so the code says roughly when a number was issued rather than where it sits.
Each holds its own blocks and its own carrier mix, so a 443 number and a 410 number from the same street can report different line types. Filtering Baltimore by area code needs all 3 of them.
443 is not confined to Baltimore itself: its blocks sit across 81 rate centres, named in the table below.
Maryland is split across 6 area codes — 240, 443, 301, 410, 667, 227. By allocated blocks 443 is the second largest of them, holding 25% of the Maryland total.
Where 443 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why Catonsvl and Cockeysvl are shortened. Names are reproduced as recorded rather than expanded — the abbreviation is the key the block data is filed under.
| Rate centre | Blocks | Share of 443 |
|---|---|---|
| Baltimore | 1,675 | 22% |
| Annapolis | 358 | 5% |
| Towson | 352 | 5% |
| Columbia | 311 | 4% |
| Glenburnie | 276 | 4% |
| Pikesville | 221 | 3% |
| Bel Air | 199 | 3% |
| Catonsvl | 190 | 2% |
| Salisbury | 169 | 2% |
| Aberdeen | 165 | 2% |
| Essex | 154 | 2% |
| Parkville | 153 | 2% |
| Westminstr | 135 | 2% |
| Elkton | 134 | 2% |
| Woodlawn | 133 | 2% |
| Cockeysvl | 127 | 2% |
| Dundalk | 109 | 1% |
| Fallston | 100 | 1% |
| Severna Pk | 100 | 1% |
| Arbutus | 98 | 1% |
| Princefrck | 98 | 1% |
| Severn | 98 | 1% |
| Edgewood | 97 | 1% |
| Randallstn | 97 | 1% |
57 further rate centres in 443 hold fewer blocks than these.
Carriers holding the most 443 blocks
Verizon Wireless1,086 blocks
AT&T Wireless773 blocks
Omnipoint Communications Cap Operations, Llc704 blocks
T-Mobile USA, Inc.697 blocks
Onvoy483 blocks
Paetec Itel, Llc471 blocks
The largest holder, Verizon Wireless, has 14% of the code.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 443 number still reports the carrier it started with. Closing that gap needs a live query against the routing database. How line type is derived.
Check a single 443 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 443?
Area code 443 covers Baltimore, Maryland. It is not the only code there: 410, 667 are overlays on the same rate centres, so a Baltimore, Maryland number can start with any of them.
Is a 443 number a mobile or a landline?
It can be either, and the digits do not say which. North American mobile and landline numbers share the same ranges, so the answer comes from the carrier holding the block. In 443 the split runs 48% mobile, 40% landline and 12% VoIP, so mobile is the most likely single answer.
Which carriers hold 443 numbers?
The largest holders are Verizon Wireless, AT&T Wireless, Omnipoint Communications Cap Operations, Llc. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 443 numbers are there?
The code holds 7,726 allocated blocks in our copy of the numbering plan. A block is 1,000 or 10,000 consecutive numbers depending on how deeply it has been pooled, so 443 covers on the order of 7,726,000 possible numbers — most of which have never been issued to anyone.