Company lists · Data refreshed September 2026

Top 25 Calling companies based in the United States

Name: Calling companies based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 1,952 companies tracked

RevenueBase identified 1,952 calling companies headquartered in the United States as of September 2026 and tracks 46,457 professional contacts across them, including 10,572 with verified work emails. New York is the largest hub.

This list covers calling companies headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 21, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 21, 2026 86% judged on-target in blind review

1,952Companies

46,457Contacts tracked

10,572Verified emails

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The 25 largest calling companies based in the United States

Ranked by team size

Top 25 of 1,952 calling companies based in the United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to calling companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Windstream	Indirect evidence	Little Rock, AR, United StatesHQ checked Sep 21, 2026	10001+	7,275 contacts →
	Indirect evidence “Windstream and Uniti have merged - Please follow us at Uniti Group, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
2	Cable ONE	Indirect evidence	Phoenix, AZ, United StatesHQ checked Sep 21, 2026	1,001-5,000	6,379 contacts →
	Indirect evidence “Cable One Business offers scalable, reliable, and efficient solutions so that the businesses we serve can be successful.” Source: RevenueBase Database · checked Sep 21, 2026
3	Spectrum Business	Indirect evidence	Stamford, CT, United StatesHQ checked Sep 21, 2026	10001+	3,044 contacts →
	Indirect evidence “Our story starts with understanding that connectivity powers everything you do, and we make it stronger.” Source: RevenueBase Database · checked Sep 21, 2026
4	Granite Telecommunications	Indirect evidence	Quincy, MA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,270 contacts →
	Indirect evidence “Granite is a dynamic and rapidly growing company serving the exciting and demanding Telecommunications market.” Source: RevenueBase Database · checked Sep 21, 2026
5	Integra	Indirect evidence	Vancouver, WA, United StatesHQ checked Sep 21, 2026	501-1,000	1,133 contacts →
	Indirect evidence “Integra is Allstream.” Source: RevenueBase Database · checked Sep 21, 2026
6	Ooma, INC	Indirect evidence	Sunnyvale, CA, United StatesHQ checked Sep 21, 2026	501-1,000	606 contacts →
	Indirect evidence “Ooma delivers phone, messaging, video and advanced communications services that are easy to implement and provide great value.” Source: RevenueBase Database · checked Sep 21, 2026
7	Telepacific Communications TPX Communications	Indirect evidence	Los Angeles, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	542 contacts →
	Indirect evidence “TelePacific company is now TPx Communications.” Source: RevenueBase Database · checked Sep 21, 2026
8	NEW Horizon Communications	Indirect evidence	Concord, MA, United StatesHQ checked Sep 21, 2026	51-200	435 contacts →
	Indirect evidence “NHC is THE communications STACK provider™.” Source: RevenueBase Database · checked Sep 21, 2026
9	Ritter Communications	Indirect evidence	Jonesboro, AR, United StatesHQ checked Sep 21, 2026	201-500	398 contacts →
	Indirect evidence “At Ritter Communications, we have over a century-long tradition of providing quality residential and business communication services all across Arkansas.” Source: RevenueBase Database · checked Sep 21, 2026
10	ACS	Indirect evidence	Lake Mary, FL, United StatesHQ checked Sep 21, 2026	n/a	358 contacts →
	Indirect evidence “ACS has over three decades of experience and unparalleled expertise in the assessment and implementation of voice and data platforms and can provide solutions for telephone…” Source: RevenueBase Database · checked Sep 21, 2026
11	BCM ONE	Indirect evidence	New York, NY, United StatesHQ checked Sep 21, 2026	501-1,000	308 contacts →
	Indirect evidence “Founded in 1992, BCM One is a corporate communications company that powers business connectivity for organizations ranging from SMBs to global enterprises.” Source: RevenueBase Database · checked Sep 21, 2026
12	Calltend INC	Indirect evidence	Los Angeles, TX, United StatesHQ checked Sep 21, 2026	51-200	289 contacts →
	Indirect evidence “Current Vertical Focus: Real Estate - Lead Generation, Lead Conversion, Lead Qualification, Agent Recruiting Mortgage - Lead Conversion, Lead Qualification Insurance - Lead…” Source: RevenueBase Database · checked Sep 21, 2026
13	ACC Business	Indirect evidence	Rochester, NY, United StatesHQ checked Sep 21, 2026	51-200	260 contacts →
	Indirect evidence “ACC Business was founded on a simple idea: provide small to mid-sized businesses first-rate telecom services with dedicated customer service, all at a competitive price.” Source: RevenueBase Database · checked Sep 21, 2026
14	Optimum Business	Indirect evidence	Bethpage, United StatesHQ checked Sep 21, 2026	201-500	210 contacts →
	Indirect evidence “Empower your business with fast, secure, and reliable connectivity solutions-all with the flexibility and support you deserve.” Source: RevenueBase Database · checked Sep 21, 2026
15	Forerunner Technologies, INC	Indirect evidence	Edgewood, NY, United StatesHQ checked Sep 21, 2026	51-200	184 contacts →
	Indirect evidence “Established in 1988, Forerunner Technologies, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
16	Firstcomm	Indirect evidence	Fairlawn, OH, United StatesHQ checked Sep 21, 2026	51-200	174 contacts →
	Indirect evidence “FirstComm delivers smarter business communications and IT solutions that help organizations connect, collaborate, and scale with confidence.” Source: RevenueBase Database · checked Sep 21, 2026
17	Fortis	Indirect evidence	Sacramento, CA, United StatesHQ checked Sep 21, 2026	n/a	170 contacts →
	Indirect evidence “Fortis is a Sacramento Area provider of managed IT services, hosted VoIP, and high speed, redundant internet.” Source: RevenueBase Database · checked Sep 21, 2026
18	Edge Communications	Indirect evidence	Plano, TX, United StatesHQ checked Sep 21, 2026	51-200	168 contacts →
	Indirect evidence “Edge is an innovative provider of communications, data, systems security and business technology services.” Source: RevenueBase Database · checked Sep 21, 2026
19	Zultys	Indirect evidence	Sunnyvale, CA, United StatesHQ checked Sep 21, 2026	51-200	159 contacts →
	Indirect evidence “Zultys is a premier provider of omnichannel, Unified Communications, hosted business phone services and premise-based communications systems.” Source: RevenueBase Database · checked Sep 21, 2026
20	IT Voice	Indirect evidence	Birmingham, AL, United StatesHQ checked Sep 21, 2026	51-200	154 contacts →
	Indirect evidence “IT Voice specializes in Managed IT and VoIP solutions.” Source: RevenueBase Database · checked Sep 21, 2026
21	In-Telecom	Indirect evidence	Slidell, LA, United StatesHQ checked Sep 21, 2026	51-200	151 contacts →
	Indirect evidence “In-Telecom offers a full spectrum of solutions such as VoIP phones, access control, unparalleled customer service, IT consulting, and quality workmanship from our experienced…” Source: RevenueBase Database · checked Sep 21, 2026
22	Unimax	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 21, 2026	51-200	133 contacts →
	Indirect evidence “Unimax believes that administering PBX and voice messaging systems can be far less complex and costly, while delivering better service levels.” Source: RevenueBase Database · checked Sep 21, 2026
23	Powernet CO	Indirect evidence	Cincinnati, OH, United StatesHQ checked Sep 21, 2026	51-200	128 contacts →
	Indirect evidence “Built from a foundation of integrity and strong business ethics, Powernet was established in 1992 in the basement of President Bernie Stevens' Cincinnati home.” Source: RevenueBase Database · checked Sep 21, 2026
24	Transcom Telecommunications	Indirect evidence	Signal Hill, CA, United StatesHQ checked Sep 21, 2026	11-50	127 contacts →
	Indirect evidence “Transcom Telecommunications (formerly called "Transcom Services") is a Veteran Owned Business founded in 1986 on 3 core ideas.” Source: RevenueBase Database · checked Sep 21, 2026
25	Altura Communication Solutions	Indirect evidence	Fullerton, CA, United StatesHQ checked Sep 21, 2026	201-500	123 contacts →
	Indirect evidence “Altura Communication Solutions, with offices nationwide, is one of Avaya's largest Diamond Business Partners and a leading provider of communication-enabled solutions and…” Source: RevenueBase Database · checked Sep 21, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: calling companies. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names calling companies.
Partial evidence: Its own public description names part of calling companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name calling companies. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 1,952 calling companies based in the United States

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Calling companies based in the United States at a glance

As of Sep 21, 2026

22.8%Verified-email coverage

23.8Average contacts per company

11-50Median size (employees)

3.0%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

863

11-50

853

51-200

175

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 1,952 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among calling companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “calling companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names calling companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among calling companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 10,572 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 21, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Calling companies by metro

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names calling companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many calling companies are there based in the United States?

RevenueBase identified 1,952 calling companies headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Windstream, headquartered in Little Rock, tops this list with the largest team on record.

Which city has the most calling companies?

New York leads with 59 headquartered companies, followed by Houston (32) and Dallas (28).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 10,572 verified decision-maker contacts tracked across these 1,952 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 21, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.