Phone numbers in Catonsville, Maryland
Catonsville has 70 phone prefixes in area codes 410, 443, 667.
Biggest holders: AT&T Mobility, Verizon (local phone), T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 70%
- Local phone company 10%
- Internet / business phone carrier 19%
- Phone company 1%
Every prefix in Catonsville
Search the first six digits of a number in this list. If it's here, the number started in Catonsville with the carrier shown. If it isn't, check the Maryland page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 410-206 | AT&T Mobility | Mobile carrier | – |
| 410-227 | AT&T Mobility | Mobile carrier | – |
| 410-245 | AT&T Mobility | Mobile carrier | – |
| 410-292 | AT&T Mobility | Mobile carrier | – |
| 410-294 | AT&T Mobility | Mobile carrier | – |
| 410-302 | AT&T Mobility | Mobile carrier | – |
| 410-370 | AT&T Mobility | Mobile carrier | – |
| 410-402 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 410-428 | AT&T Mobility | Mobile carrier | – |
| 410-440 | AT&T Mobility | Mobile carrier | – |
| 410-446 | AT&T Mobility | Mobile carrier | – |
| 410-455 | Verizon (local phone) | Local phone company | – |
| 410-491 | AT&T Mobility | Mobile carrier | – |
| 410-530 | AT&T Mobility | Mobile carrier | – |
| 410-599 | AT&T Mobility | Mobile carrier | – |
| 410-608 | AT&T Mobility | Mobile carrier | – |
| 410-615 | AT&T Mobility | Mobile carrier | – |
| 410-718 | AT&T Mobility | Mobile carrier | – |
| 410-719 | Verizon (local phone) | Local phone company | – |
| 410-733 | AT&T Mobility | Mobile carrier | – |
| 410-744 | Verizon (local phone) | Local phone company | – |
| 410-747 | Verizon (local phone) | Local phone company | – |
| 410-788 | Verizon (local phone) | Local phone company | – |
| 410-802 | AT&T Mobility | Mobile carrier | – |
| 410-807 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 410-818 | Teleport Communications America | Internet / business phone carrier | – |
| 410-852 | AT&T Mobility | Mobile carrier | – |
| 410-868 | AT&T Mobility | Mobile carrier | – |
| 410-869 | Verizon (local phone) | Local phone company | – |
| 410-917 | AT&T Mobility | Mobile carrier | – |
| 410-926 | AT&T Mobility | Mobile carrier | – |
| 410-948 | AT&T Mobility | Mobile carrier | – |
| 410-971 | AT&T Mobility | Mobile carrier | – |
| 410-978 | AT&T Mobility | Mobile carrier | – |
| 410-979 | AT&T Mobility | Mobile carrier | – |
| 443-251 | Onvoy | Internet / business phone carrier | – |
| 443-315 | AT&T Mobility | Mobile carrier | – |
| 443-341 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 443-474 | AT&T Mobility | Mobile carrier | – |
| 443-498 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 443-514 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 443-520 | AT&T Mobility | Mobile carrier | – |
| 443-612 | Verizon (local phone) | Local phone company | – |
| 443-631 | AT&T Mobility | Mobile carrier | 2005 |
| 443-636 | T-Mobile (including Sprint) | Mobile carrier | – |
| 443-668 | AT&T Mobility | Mobile carrier | 2001 |
| 443-670 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 443-697 | Global Naps South | Phone company | – |
| 443-710 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 443-765 | AT&T Mobility | Mobile carrier | 2001 |
| 443-830 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 443-840 | AT&T Mobility | Mobile carrier | 2005 |
| 443-851 | T-Mobile (including Sprint) | Mobile carrier | 2001 |
| 443-860 | AT&T Mobility | Mobile carrier | 2005 |
| 443-887 | Windstream (PAETEC) | Internet / business phone carrier | 2010 |
| 443-980 | AT&T Mobility | Mobile carrier | – |
| 443-996 | AT&T Mobility | Mobile carrier | – |
| 667-345 | Core Communications | Internet / business phone carrier | 2018 |
| 667-369 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 667-419 | AT&T Mobility | Mobile carrier | 2022 |
| 667-432 | AT&T Mobility | Mobile carrier | 2023 |
| 667-433 | AT&T Mobility | Mobile carrier | 2023 |
| 667-438 | AT&T Mobility | Mobile carrier | 2023 |
| 667-445 | T-Mobile (including Sprint) | Mobile carrier | 2023 |
| 667-452 | AT&T Mobility | Mobile carrier | 2023 |
| 667-482 | AT&T Mobility | Mobile carrier | 2024 |
| 667-517 | T-Mobile (including Sprint) | Mobile carrier | 2024 |
| 667-557 | AT&T Mobility | Mobile carrier | 2026 |
| 667-626 | TON80 Communications | Internet / business phone carrier | 2022 |
| 667-802 | T-Mobile (including Sprint) | Mobile carrier | 2015 |
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. Source: NANPA central office code records, 2026-10-10.