Recent prefix assignments
0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026
The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.
| Assigned | NPA-NXX | Thousands-blocks taken (last-4 opening) | Code holder | OCN | Rate center | State |
|---|---|---|---|---|---|---|
| — | 443-778 | 1XXX2XXX9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | WATERLO236 | MD |
| — | 443-779 | 0–9 XXXall 10 · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | ABERDEEN | MD |
| — | 443-781 | 0–9 XXXall 10 · 5 holders which blocks → | ONVOY, LLC - MD | 876D | ARGRGBSNIS | MD |
| — | 443-782 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | ANNAPOLIS | MD |
| — | 443-783 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | SALISBURY | MD |
| — | 443-784 | 0–9 XXXall 10 · 4 holders which blocks → | TELEPORT COMMUNICATIONS AMERICA, LLC - MD | 7325 | ARGRGBSNIS | MD |
| — | 443-785 | not yet reported which blocks → | ONVOY, LLC - MD | 876D | ARBUTUS | MD |
| — | 443-786 | 8XXX9XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | EASTON | MD |
| — | 443-787 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | PAETEC ITEL, LLC | 829J | BEL AIR | MD |
| — | 443-788 | 0–9 XXXall 10 · 3 holders which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | ABERDEEN | MD |
| — | 443-789 | 3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | WESTMINSTR | MD |
| — | 443-791 | 3XXX5XXX6XXX7XXX8XXX · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | TOWSON | MD |
| — | 443-793 | 2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | PARKVILLE | MD |
| — | 443-794 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BALTIMORE | MD |
| — | 443-795 | 1XXX2XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SEVERN | MD |
| — | 443-796 | 1XXX2XXX3XXX5XXX6XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | PIKESVILLE | MD |
| — | 443-797 | 2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | TOWSON | MD |
| — | 443-798 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 4 holders which blocks → | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | TOWSON | MD |
| — | 443-801 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-802 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-803 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-804 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-807 | 2XXX4XXX5XXX · 3 holders which blocks → | METROPCS, INC. | 5562 | FALLSTON | MD |
| — | 443-811 | not yet reported which blocks → | MULTIPLE OCN LISTING | MULT | XXXXXXXXXX | MD |
| — | 443-815 | 1XXX2XXX3XXX4XXX7XXX8XXX9XXX · 4 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | ESSEX | MD |
| — | 443-816 | 3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | SEVERNA PK | MD |
| — | 443-817 | 2XXX3XXX7XXX8XXX · 2 holders which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC | 7229 | ARGRGBSNIS | MD |
| — | 443-820 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | ELKRIDGE | MD |
| — | 443-822 | 2XXX which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | ANNAPOLIS | MD |
| — | 443-827 | 5XXX6XXX7XXX8XXX9XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 443-829 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-831 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BALTIMORE | MD |
| — | 443-832 | 0XXX1XXX2XXX3XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | LEVEL 3 COMMUNICATIONS, LLC - MD | 6119 | COLUMBIA | MD |
| — | 443-833 | 0–9 XXXall 10 · 6 holders which blocks → | PAETEC ITEL, LLC | 829J | ARBUTUS | MD |
| — | 443-834 | 0–9 XXXall 10 · 2 holders which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | TOWSON | MD |
| — | 443-838 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BALTIMORE | MD |
| — | 443-841 | 0XXX1XXX2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 443-843 | 0XXX1XXX2XXX3XXX4XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | HAVREGRACE | MD |
| — | 443-845 | 3XXX4XXX5XXX which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 443-846 | 0–9 XXXall 10 · 2 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | TOWSON | MD |
| — | 443-848 | 0–9 XXXall 10 · 4 holders which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | GLENBURNIE | MD |
| — | 443-857 | not yet reported which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-858 | not yet reported which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 443-859 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | SALISBURY | MD |
| — | 443-867 | 0XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | GLENBURNIE | MD |
| — | 443-868 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | ESSEX | MD |
| — | 443-870 | 0XXX1XXX3XXX4XXX5XXX · 3 holders which blocks → | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | PIKESVILLE | MD |
| — | 443-871 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | ANNAPOLIS | MD |
| — | 443-872 | 1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → | PAETEC ITEL, LLC | 829J | BALTIMORE | MD |
| — | 443-874 | 0XXX1XXX2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 3 holders which blocks → | PAETEC ITEL, LLC | 829J | BALTIMORE | MD |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.