altafiber phone number blocks and OCNs in the US

altafiber holds 3 million phone numbers in the United States, 0.2% of the numbers NANPA’s table of 2026-09-27 lists as allocated there, under 6 operating company numbers (OCNs); the largest, CINCINNATI BELL (OCN 9348), holds 2.8 million. The carrier a phone lookup names for a number is the holder of the block the number sits in, as the regulator lists it: the original allocation, not the caller, the app or the network that serves a ported number today.

Brand	altafiber
Numbers held	3,030,000 (0.2% of the allocated numbers in NANPA’s table)
Operating company numbers	6
Codes held	337
Thousands-blocks held	918
Table	NANPA numbering reports, file dated 2026-09-27
Terms	no terms of use published (NANPA)
Grouped by	Spaw’s carrier brand map of 2026-09-24
Region	United States

The legal entities NANPA lists

Every holder in NANPA’s table that the brand map groups under altafiber, by the numbers allocated to it and with its operating company number (OCN), the code the table identifies a carrier by. Names are printed as the regulator writes them. Holdings are counted in numbers, not table rows, because rows differ in size: a central office code (NPA-NXX) is 10,000 numbers and a thousands-block 1,000. A pooled code counts for its code holder only where no thousands-block row of the table covers it, so no number is counted twice.

holder	ocn	codes	thousands-blocks	numbers	read as
CINCINNATI BELL	9348	312	713	2,785,000	unsettled
CINCINNATI BELL EXTENDED TERRITORIES LLC - OH	309B	22	153	193,000	unsettled
CINBELL EXT TERR LLC DBA ALTAFIBER CONNECTED SVCS	600F	3	38	38,000	unsettled
CINBELL EXT TERR LLC DBA ALTAFIBER CONNECTED SVCS	593F	0	10	10,000	unsettled
CINBELL EXT TERR LLC DBA ALTAFIBER CONNECTED SVCS	3638	0	3	3,000	unsettled
CINCINNATI BELL EXTENDED TERRITORIES LLC - IN	184J	0	1	1,000	unsettled

How a lookup reads these numbers

The North American plan leaves a number’s line type to the holder of its block, so a lookup reads it from the holder: 0.0% of altafiber’s numbers read as VoIP, 0.0% as mobile, and for 100.0% the holder settles neither, so the line type stays fixed_line_or_mobile.

The reading is Spaw’s classification of each holder: the holder’s regulatory filing (in the US its FCC Form 499 filing type) and its own description, matched on the name the regulator’s table gives it. It is a lower bound, not a measurement of the numbers, and it says what a lookup answers, not what altafiber is.

The area codes with most of its numbers

altafiber’s entities hold numbers under 6 area codes. The share is its part of the numbers NANPA lists as allocated under each code.

code	place	numbers	share of the code
513	Cincinnati, OH	2,402,000	30.7%
859	Kentucky	484,000	9.2%
937	Ohio	121,000	1.6%
812	Indiana	16,000	0.2%
326	Ohio	6,000	1.0%
930	Indiana	1,000	0.1%

Thousands-blocks in pooled codes

In a pooled US code NANPA assigns the code’s ten thousands-blocks one by one, often to carriers other than the code holder, and a lookup names the holder of the number’s own thousands-block where NANPA lists one. altafiber’s entities hold 918 thousands-blocks: 776 inside codes its own entities hold, 136 inside codes of other brands and 6 inside codes of holders the brand map does not group, which this page counts but does not name.

code holder’s brand	altafiber’s blocks inside
Lumen	45
AT&T	24
Inteliquent	17
Windstream	15
Verizon	12
Frontier	11

Other holders hold 473 thousands-blocks inside altafiber’s codes, 13 of them holders the brand map does not group. The largest: Verizon 90, T-Mobile 79, Bandwidth 74, AT&T 58, Inteliquent 52, Lumen 45.

Assignments by year

The codes and thousands-blocks the table still lists under altafiber’s entities, by the year NANPA dates their assignment. A block returned since is no longer in the table, so earlier years read low; 25.4% of the rows carry a date. NANPA dates nothing before 2001 and no retained block.

year	codes	thousands-blocks	numbers
2026	0	12	12,000
2025	0	10	10,000
2024	0	2	2,000
2023	0	4	4,000
2022	0	2	2,000
2020	0	2	2,000
2019	1	1	1,000
2018	0	3	3,000
2017	1	1	1,000
2016	0	2	2,000
2001–2015	29	249	269,000

What this page cannot say

A regulator’s table records the original allocation of each block, never who serves a number today: a number ported away from altafiber keeps its block, and a lookup still names the block’s holder for it.
The carrier a lookup names is not the caller, the app or the subscriber. Caller ID can be spoofed, so the holder of a calling number’s block may not have carried the call at all.
Spaw does no reverse lookup and names no subscriber: nothing here says who owns or uses any number.
Shares are shares of the regulator’s own table, not of subscribers, lines in service or traffic.
In a pooled US code a lookup names the holder of the number’s own thousands-block where NANPA lists one, otherwise the code holder; Canada’s table is code-level.
The grouping under altafiber is Spaw’s carrier brand map of 2026-09-24: legal entities, subsidiaries and former names under the brand the network trades as today. Networks change hands, and the map is reviewed at least yearly.

altafiber and the other brand names on this page are trademarks of their owners, used only to name the networks the regulators’ tables list. Spaw is not affiliated with any of them.

Other carriers in the United States

NANPA numbering reports file dated 2026-09-27 · carrier brand map 2026-09-24 · page changed 2026-09-27

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