Recent prefix assignments
375 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/30/2026
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 |
|---|---|---|---|---|---|---|
| — | 410-227 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CATONSVL | MD |
| — | 410-228 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | CAMBRIDGE | MD |
| — | 410-229 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | COCKEYSVL | MD |
| — | 410-230 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-231 | 2XXX3XXX5XXX7XXX · 4 holders which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | SOLOMONS | MD |
| — | 410-232 | not yet reported which blocks → | SPOK, INC. | 6630 | BALTIMORE | MD |
| — | 410-233 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-234 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-235 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-236 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | TOWSON | MD |
| — | 410-237 | 0XXX1XXX4XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-238 | 9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | ESSEX | MD |
| — | 410-239 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | REISTERSTN | MD |
| — | 410-241 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 410-242 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ARBUTUS | MD |
| — | 410-243 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-244 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-245 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CATONSVL | MD |
| — | 410-246 | 4XXX which blocks → | MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MD | 7228 | BALTIMORE | MD |
| — | 410-247 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ARBUTUS | MD |
| — | 410-248 | 5XXX7XXX · 2 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | PARKVILLE | MD |
| — | 410-249 | none assigned yet which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-250 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | OCEAN CITY | MD |
| — | 410-251 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | SALISBURY | MD |
| — | 410-252 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-253 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | EASTON | MD |
| — | 410-254 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-255 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ARGRGBSNIS | MD |
| — | 410-256 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | PARKVILLE | MD |
| — | 410-257 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | NORTHBEACH | MD |
| — | 410-258 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 410-259 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | WESTMINSTR | MD |
| — | 410-260 | 0XXX9XXX · 2 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | SEVERNA PK | MD |
| — | 410-261 | 0XXX4XXX6XXX9XXX · 3 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-262 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 410-263 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ANNAPOLIS | MD |
| — | 410-264 | 1XXX2XXX6XXX · 2 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | WATERLO236 | MD |
| — | 410-265 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | WOODLAWN | MD |
| — | 410-266 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ANNAPOLIS | MD |
| — | 410-267 | 3XXX4XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | ANNAPOLIS | MD |
| — | 410-268 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ANNAPOLIS | MD |
| — | 410-269 | 3XXX9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | SEVERNA PK | MD |
| — | 410-270 | not yet reported which blocks → | REDI-CALL COMMUNICATIONS CO. | 6810 | SALISBURY | MD |
| — | 410-271 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | ANNAPOLIS | MD |
| — | 410-272 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ABERDEEN | MD |
| — | 410-273 | 3XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | ABERDEEN | MD |
| — | 410-274 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 410-275 | 0XXX3XXX4XXX5XXX6XXX7XXX · 6 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | CECILTON | MD |
| — | 410-276 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-277 | 1XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | WOODLAWN | MD |
Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/30/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.