Company lists · Data refreshed September 2026
Top 25 Business phone system software companies based in the United States
RevenueBase identified 531 business phone system software companies headquartered in the United States as of September 2026 and tracks 21,136 professional contacts across them, including 5,272 with verified work emails. Miami is the largest hub.
This list covers business phone system software 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 27, 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.
The 25 largest business phone system software companies based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 10,510 contacts → | ||||
Indirect evidence “At Avaya, we give our customers the freedom to take their business in the directions that benefit them most.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 2,320 contacts → | ||||
Indirect evidence “As the leader in cloud communications and IT, GoTo addresses real-world challenges with practical innovations and a customer-first mindset.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 606 contacts → | ||||
Partial evidence “Ooma delivers phone, messaging, video and advanced communications services that are easy to implement and provide great value.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 527 contacts → | ||||
Partial evidence “Incorporated in 1987 and headquartered in Cincinnati, Ohio, London Computer Systems (LCS) develops innovative business technologies used in all 50 states and several global…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 398 contacts → | ||||
Partial evidence “Founded in 2008 by veteran telecommunication entrepreneurs, Phone.com provides over businesses with comprehensive, flexible, and reliable cloud-based communication and…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 252 contacts → | ||||
Partial evidence “BroadSoft, now part of Cisco, is the leading provider of software and services that enable mobile, fixed-line and cable service providers to offer Unified Communications over…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 212 contacts → | ||||
Indirect evidence “Communication is the backbone of every business.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 206 contacts → | ||||
Indirect evidence “At Hiya, we are revolutionizing the voice communication experience, making it more productive and secure.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 175 contacts → | ||||
Indirect evidence “Vertical Communications is a leading provider of communications platforms and applications that enable critical business workflows for enterprises across a variety of industries…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 159 contacts → | ||||
Strong evidence “Zultys is a premier provider of omnichannel, Unified Communications, hosted business phone services and premise-based communications systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 133 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 121 contacts → | ||||
Strong evidence “Founded in 1987, Estech Systems (ESI), a Crexendo® company, delivers high-performance phone systems designed for growing businesses.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 118 contacts → | ||||
Partial evidence “Amtelco has been a family-owned communication software company since 1976 and devoted to providing secure, stable, and critical communication solutions for healthcare, contact…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 108 contacts → | ||||
Indirect evidence “TeleCloud delivers modern Unified Communications, VoIP, and AI-powered communication solutions, paired with the personal, local service businesses deserve.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 103 contacts → | ||||
Indirect evidence “Founded in 2006 in Sarasota, Florida, Star2Star Communications delivers the World's Leading Hybrid Cloud Communications Solution.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 91 contacts → | ||||
Strong evidence “Alliance Global is a cloud-based business phone system provider exclusively for organizations that require professional communication features.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 75 contacts → | ||||
Indirect evidence “Established more than 20 years ago, NetFortris has grown to become the leading provider of secure cloud communication solutions to forward-thinking, mid-sized and enterprise…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 68 contacts → | ||||
Strong evidence “Business Class Phone Systems & Service with support & functionality to exceed your communication needs.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 65 contacts → | ||||
Indirect evidence “From around the corner, to around the globe, COA Network delivers the tools and technology that makes building and managing your business easier.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 63 contacts → | ||||
Indirect evidence “Lightspeed Voice is an AI-powered VoIP solutions provider at the forefront of transforming business communications.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 62 contacts → | ||||
Indirect evidence “FluentStream is the leading communications provider for small to medium business and has been recognized by Inc.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 60 contacts → | ||||
Indirect evidence “It’s no secret that staying connected and accessible is absolutely crucial in today’s business environment.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 58 contacts → | ||||
Indirect evidence “Digium®, Inc.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 57 contacts → | ||||
Indirect evidence “2600Hz modernizes the way businesses communicate with KAZOO-a cloud-based unified communications solution.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 55 contacts → | ||||
Indirect evidence “West IP Communications, a wholly owned subsidiary of West Corporation, is a leading provider of cloud-based communications for the enterprise - including MPLS-based application…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
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: business phone system software 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 business phone system software companies.
- Partial evidence
- Its own public description names part of business phone system software companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name business phone system software 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 531 business phone system software companies based in the United States
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Business phone system software companies based in the United States at a glance
As of Sep 27, 2026Companies by employee count
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 531 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 business phone system software 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 “business phone system software 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 business phone system software 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 business phone system software 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, 5,272 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 27, 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.
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 business phone system software 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 business phone system software companies are there based in the United States?
RevenueBase identified 531 business phone system software 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?
AVAYA, headquartered in Morristown, tops this list with the largest team on record.
Which city has the most business phone system software companies?
Miami leads with 15 headquartered companies, followed by New York (14) and Dallas (9).
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 5,272 verified decision-maker contacts tracked across these 531 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 27, 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.
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