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 |
|---|---|---|---|---|---|---|
| — | 410-331 | not yet reported which blocks → | SPOK, INC. | 6630 | ELKRIDGE | MD |
| — | 410-332 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-333 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-334 | 0XXX1XXX4XXX8XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | SALISBURY | MD |
| — | 410-335 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | CHASE | MD |
| — | 410-336 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BALTIMORE | MD |
| — | 410-337 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-338 | 9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-339 | 0XXX1XXX2XXX8XXX9XXX · 3 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-340 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | BALTIMORE | MD |
| — | 410-341 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | SALISBURY | MD |
| — | 410-342 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-343 | 4XXX5XXX6XXX7XXX8XXX9XXX · 5 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | SPARKSGLNC | MD |
| — | 410-344 | 2XXX3XXX4XXX5XXX6XXX7XXX8XXX · 5 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | CHASE | MD |
| — | 410-345 | 0XXX9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | PIKESVILLE | MD |
| — | 410-346 | 0XXX1XXX2XXX3XXX4XXX5XXX8XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | SILVER RUN | MD |
| — | 410-347 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-348 | 0XXX1XXX3XXX4XXX6XXX7XXX8XXX · 6 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | STILL POND | MD |
| — | 410-349 | 5XXX6XXX7XXX · 3 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | ANNAPOLIS | MD |
| — | 410-350 | 1XXX4XXX5XXX6XXX9XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-351 | not yet reported which blocks → | SPOK, INC. | 6630 | BALTIMORE | MD |
| — | 410-352 | 0XXX1XXX2XXX4XXX6XXX7XXX8XXX · 5 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | BISHOPVL | MD |
| — | 410-353 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | ANNAPOLIS | MD |
| — | 410-354 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-355 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-356 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | PIKESVILLE | MD |
| — | 410-357 | 1XXX2XXX3XXX6XXX7XXX · 3 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | PARKTON | MD |
| — | 410-358 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-359 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-360 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ARGRGBSNIS | MD |
| — | 410-361 | 0XXX1XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-362 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-363 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | PIKESVILLE | MD |
| — | 410-364 | 0XXX1XXX2XXX3XXX4XXX6XXX7XXX8XXX · 7 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | HILLSBORO | MD |
| — | 410-365 | none assigned yet which blocks → | OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC | 6855 | BALTIMORE | MD |
| — | 410-366 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-367 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-368 | 0XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | BALTIMORE | MD |
| — | 410-369 | 6XXX8XXX which blocks → | LEVEL 3 TELECOM OF MARYLAND, LLC - MD | 7591 | BALTIMORE | MD |
| — | 410-370 | not yet reported which blocks → | NEW CINGULAR WIRELESS PCS, LLC - DC | 4036 | CATONSVL | MD |
| — | 410-371 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 410-372 | 3XXX5XXX6XXX7XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-373 | not yet reported which blocks → | SPOK, INC. | 6630 | TOWSON | MD |
| — | 410-374 | 7XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | HAMPSTEAD | MD |
| — | 410-375 | not yet reported which blocks → | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MD | 6395 | BALTIMORE | MD |
| — | 410-376 | 1XXX4XXX5XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → | VERIZON MARYLAND, INC. | 9212 | VIENNA | MD |
| — | 410-377 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | TOWSON | MD |
| — | 410-378 | 7XXX which blocks → | VERIZON MARYLAND, INC. | 9212 | PT DEPOSIT | MD |
| — | 410-379 | not yet reported which blocks → | VERIZON MARYLAND, INC. | 9212 | ELKRIDGE | MD |
| — | 410-380 | not yet reported which blocks → | REDI-CALL COMMUNICATIONS CO. | 6810 | SALISBURY | 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.