NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

Area code 350 prefixes

88 of the 786 possible NXX blocks are assigned in area code 350 (11.2% of capacity), spread across 41 rate centers and 17 holders. The largest holders are ONVOY, LLC - CA (20 blocks, 22.7%), ONVOY SPECTRUM, LLC (17 blocks, 19.3%), NEW CINGULAR WIRELESS PCS, LLC (12 blocks, 13.6%). Grouped by brand, Onvoy accounts for 20 blocks; brand-attributable holders cover 80% of the code, and the rest are CLECs, VoIP wholesalers and regional carriers that trade under their own names. The assignment records here run from 2022-09-28 to 2026-09-21, with 23 blocks handed out in 2023 alone. 88 blocks (100%) are in thousands-block pooling, meaning the block is shared between carriers in 1,000-number lots rather than held whole – which is why a single NXX can serve several carriers at once. 5 assigned blocks (259, 260, 261, 263, 264) are not yet in service: assigned to a carrier but not open for calls, so a caller ID from one is spoofed. 57 were growth assignments – additional blocks to a carrier that had already filled its earlier ones.

88 assigned blocks of 786
41 rate centers
17 holders of record
100% in thousands-block pooling

Largest holders in 350

Holder of record, as NANPA names itBrandBlocksShare
ONVOY, LLC - CA Onvoy 20 22.7%
ONVOY SPECTRUM, LLC Charter 17 19.3%
NEW CINGULAR WIRELESS PCS, LLC AT&T 12 13.6%
COMMIO, LLC – 7 8%
T-MOBILE USA, INC. T-Mobile 7 8%
TERRA NOVA TELECOM INC. – 7 8%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA Verizon 5 5.7%
COMCAST PHONE OF CALIFORNIA, LLC Comcast 2 2.3%
TELEPORT COMMUNICATIONS AMERICA, LLC - CA AT&T 2 2.3%
NUSO, LLC – 2 2.3%
BANDWIDTH.COM CLEC, LLC - CA Bandwidth 1 1.1%
PEERLESS NETWORK OF CALIFORNIA, LLC - CA Peerless 1 1.1%

Names are printed as they appear in the assignment records, which is the legal entity rather than the brand. Holding a block is not the same as serving the numbers in it: portability moves numbers between carriers and pooling splits a block between several.

Rate centers with their own page

Rate centers where at least three blocks are assigned, excluding the numbered metro zone codes. The remainder are in the full table below.

All 88 assigned blocks

One row per NXX. “Pooled” means carriers draw 1,000-number lots from the block rather than holding all 10,000, so a pooled prefix can belong to several carriers at once. “Not in service” means assigned but not yet open for calls – a caller ID from one of those is necessarily spoofed. The holder column gives the brand where the legal entity maps to one; the full legal names are in the holders table above, exactly as NANPA records them.

PrefixHolder of recordRate centerAssignedPooledIn service
350-200 Bandwidth LODI 2022-09-28 yes yes
350-201 Comcast WALLACE 2022-10-10 yes yes
350-202 COMMIO, LLC THORNTON 2022-10-28 yes yes
350-203 COMMIO, LLC DOS PALOS 2023-12-20 yes yes
350-204 T-Mobile ATWATER 2023-01-11 yes yes
350-205 Comcast PLANADA 2023-01-18 yes yes
350-206 AT&T TURLOCK 2023-02-27 yes yes
350-207 NUSO, LLC MODESTO – yes yes
350-208 Charter KNIGHTFRRY – yes yes
350-209 Peerless VALLEY SPG 2023-04-18 yes yes
350-210 Onvoy TUOLUMNE 2023-06-21 yes yes
350-212 COMMIO, LLC SUTTER CRK 2023-12-20 yes yes
350-213 COMMIO, LLC LINDEN 2023-12-20 yes yes
350-214 COMMIO, LLC VALLEY SPG 2023-12-21 yes yes
350-215 COMMIO, LLC SNELLING 2023-12-21 yes yes
350-216 COMMIO, LLC MODESTO 2023-12-21 yes yes
350-217 T-Mobile STOCKTON 2024-01-11 yes yes
350-218 T-Mobile MANTECA 2024-01-19 yes yes
350-219 AT&T STOCKTON 2024-03-14 yes yes
350-220 AT&T MODESTO 2024-03-14 yes yes
350-221 Onvoy LODI 2024-05-14 yes yes
350-222 TERRA NOVA TELECOM INC. HUGHSON 2022-10-04 yes yes
350-223 Onvoy MERCED 2024-05-14 yes yes
350-224 AT&T ATWATER 2024-05-29 yes yes
350-225 Onvoy LOS BANOS 2024-07-05 yes yes
350-226 Onvoy MODESTO 2024-07-05 yes yes
350-227 Onvoy TRACY 2024-07-05 yes yes
350-228 AT&T STOCKTON 2024-08-06 yes yes
350-229 Verizon MANTECA 2024-08-16 yes yes
350-230 AT&T MODESTO 2024-08-30 yes yes
350-231 LEAP TELECOM, LLC STOCKTON 2024-09-23 yes yes
350-232 AT&T PINECREST 2024-10-08 yes yes
350-233 T-Mobile ATWATER 2024-10-21 yes yes
350-234 AT&T JACKSON 2024-10-22 yes yes
350-235 Onvoy CLEMENTS 2022-11-18 yes yes
350-236 T-Mobile JAMESTOWN 2024-12-06 yes yes
350-237 Charter PATTERSON 2025-01-02 yes yes
350-238 Verizon MODESTO 2025-03-11 yes yes
350-239 Onvoy LOS BANOS 2025-03-13 yes yes
350-240 AT&T TURLOCK 2025-03-14 yes yes
350-241 WAVENATION, LLC STOCKTON 2025-03-21 yes yes
350-242 NUSO, LLC STOCKTON 2025-04-21 yes yes
350-243 Verizon MANTECA 2025-05-06 yes yes
350-244 Verizon JACKSON 2025-05-16 yes yes
350-245 Verizon MARIPOSA 2025-05-21 yes yes
350-246 Onvoy GALT 2025-08-13 yes yes
350-247 T-Mobile LODI 2025-08-20 yes yes
350-248 T-Mobile ATWATER 2025-08-20 yes yes
350-249 AT&T ATWATER 2025-08-22 yes yes
350-250 Onvoy TRACY 2022-09-28 yes yes
350-251 AT&T OAKDALE 2025-09-04 yes yes
350-252 AT&T TURLOCK 2025-10-09 yes yes
350-253 Charter CLEMENTS 2025-01-08 yes yes
350-254 AT&T TRACY 2025-12-10 yes yes
350-255 Onvoy MANTECA 2025-12-12 yes yes
350-256 Onvoy MODESTO 2025-12-12 yes yes
350-257 AT&T RIPON 2026-04-22 yes yes
350-258 Onvoy ATWATER 2026-06-30 yes yes
350-259 Charter LODI 2026-08-04 yes no
350-260 Onvoy DOS PALOS 2026-08-11 yes no
350-261 Onvoy MODESTO 2026-05-29 yes no
350-262 Onvoy STOCKTON 2026-08-19 yes yes
350-263 Onvoy MODESTO 2026-08-21 yes no
350-264 AT&T STOCKTON 2026-09-21 yes no
350-305 Onvoy YOSEMITE 2022-10-24 yes yes
350-333 TERRA NOVA TELECOM INC. NEWMAN 2022-10-04 yes yes
350-350 Charter STOCKTON 2023-10-25 yes yes
350-353 Dish MODESTO 2025-08-28 yes yes
350-355 Charter STOCKTON 2024-01-04 yes yes
350-444 TERRA NOVA TELECOM INC. SNELLING 2022-10-04 yes yes
350-500 Charter ATWATER 2023-11-14 yes yes
350-503 Charter MERCED 2023-11-14 yes yes
350-530 Charter ESCALON 2023-11-14 yes yes
350-550 Charter MOCCASIN 2023-11-14 yes yes
350-600 Charter OAKDALE 2023-11-17 yes yes
350-630 Charter RIVERBANK 2023-11-17 yes yes
350-666 TERRA NOVA TELECOM INC. SANANDREAS 2022-10-04 yes yes
350-750 Charter SNRA MAIN 2023-11-17 yes yes
350-777 TERRA NOVA TELECOM INC. GALT 2022-10-04 yes yes
350-867 Onvoy LE GRAND 2025-09-11 yes yes
350-880 8x8 MANTECA 2026-05-20 yes yes
350-888 TERRA NOVA TELECOM INC. GROVELAND 2022-10-04 yes yes
350-900 Charter TRACY 2023-11-17 yes yes
350-930 Charter TURLOCK 2023-11-17 yes yes
350-955 Charter WTFR DNPR 2023-11-17 yes yes
350-960 Charter WTFR MAIN 2023-11-17 yes yes
350-998 Onvoy STOCKTON 2026-06-01 yes yes
350-999 TERRA NOVA TELECOM INC. GUSTINE 2022-10-04 yes yes

Frequently asked

How many prefixes does area code 350 have?

88 NXX blocks are assigned of 786 possible. Each block is 10,000 consecutive numbers, so the code currently covers about 880 thousand-number ranges across 41 rate centers.

What do the first three digits after 350 tell me?

They identify the block, which tells you the rate center it was allocated to and the carrier that received it. They do not tell you who serves the number today: portability moves numbers between carriers, and pooling splits a block between several of them.

Is a 350 prefix tied to a specific town?

To a rate center, which is billing geography rather than a town. NANPA abbreviates rate center names to ten characters and in large metros uses zone codes, so the name is a NANPA label, not a place name.

What does “pooled” mean in the 350 table?

That the block is in thousands-block pooling: carriers draw 1,000-number lots from it instead of taking all 10,000. 88 of 350's blocks are pooled, which is how regulators slowed down area code exhaustion – and why one prefix can belong to several carriers.

Source and limits

NANPA CO Code Assignment Records, all states, utilized codes, file updated 11/01/2026 – the rows where the record's Use field is “AS” (assigned). Unavailable codes are excluded. The records say who received a block and when, not who serves a particular number today.

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