Largest phone number holders

The 36 companies below hold the most central office codes in the North American Numbering Plan, out of 197,646 prefixes in service. Open one to see its prefixes by state and by area code.

A holder is the company NANPA assigned a prefix to, under the legal name it registered. Because of number portability, a number in one of these prefixes may now be with another carrier. To see who holds the block behind a single number, use the carrier lookup.

Ranked by prefixes held

The largest holders of phone number prefixes, ranked
Rank	Holder	Type	Prefixes	Share	States and territories	Area codes
1	New Cingular Wireless PCS	No description known	18,461	9%	53	356
2	Verizon Wireless	Mobile network operator	17,577	9%	49	348
3	Onvoy	No description known	11,772	6%	48	324
4	Level 3 Communications	No description known	9,051	5%	51	326
5	T-Mobile USA	No description known	7,873	4%	34	179
6	Southwestern Bell	Landline telephone company	5,971	3%	6	43
7	Qwest	No description known	5,604	3%	15	45
8	Paetec Itel	No description known	5,547	3%	46	266
9	Mcimetro Access Transmission Services	No description known	5,539	3%	50	302
10	Pacific Bell	Landline telephone company	4,893	2%	1	30
11	Bandwidth.com CLEC	Wholesale and VoIP provider	4,804	2%	49	341
12	Southern Bell Tel & Tel	Landline telephone company	4,173	2%	5	36
13	Metropcs	No description known	3,841	2%	50	304
14	Teleport Communications America	No description known	3,830	2%	39	279
15	South Central Bell Tel	Landline telephone company	3,149	2%	8	27
16	Verizon New York	No description known	2,901	1%	2	15
17	Fractel	No description known	2,858	1%	48	255
18	Spok	No description known	1,941	<1%	38	181
19	Illinois Bell Tel	Landline telephone company	1,909	<1%	2	14
20	Comcast IP Phone	No description known	1,857	<1%	52	246
21	Aerial Communications	No description known	1,792	<1%	13	53
22	Omnipoint Communications	No description known	1,779	<1%	3	31
23	Onvoy Spectrum	No description known	1,769	<1%	51	325
24	Verizon Pennsylvania	No description known	1,587	<1%	1	10
25	Ton80 Communications	No description known	1,582	<1%	44	206
26	Verizon New Jersey	No description known	1,465	<1%	1	8
27	Verizon New England	No description known	1,420	<1%	2	10
28	Michigan Bell Tel	Landline telephone company	1,411	<1%	1	11
29	Frontier North	Landline telephone company	1,363	<1%	5	26
30	Ohio Bell Tel	Landline telephone company	1,173	<1%	1	11
31	United States Cellular	No description known	1,152	<1%	19	57
32	Verizon Maryland	No description known	1,075	<1%	1	5
33	Frontier California	Landline telephone company	1,074	<1%	1	21
34	TWC IP Enabled Services	No description known	1,055	<1%	28	116
35	Verizon Virginia	No description known	1,041	<1%	1	7
36	Centurylink	No description known	1,025	<1%	16	34

Split by holder type

We label a holder only when a public page from the company shows what it is. The others stay unlabeled, so this split counts them separately instead of guessing.

The listed holders split by type
Type	Holders	Prefixes	Share of listed prefixes
Mobile	1	17,577	12%
Landline	9	25,116	17%
Wholesale and VoIP	1	4,804	3%
No description known	25	97,817	67%

Source: NANPA central office code report dated 2026-10-17 and thousands-block report dated 2026-10-17.