Company lists · Data refreshed September 2026
Top 25 Calling services worldwide
RevenueBase identified 332 calling services worldwide as of September 2026 and tracks 5,113 professional contacts across them, including 994 with verified work emails. The United States is the largest market and London the largest hub.
This list covers calling services worldwide, 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. Country and city lists for calling services follow the table.
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 calling services worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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, 2026Thanks. The Data Team will review it. | |||||
| 2 | 430 contacts → | ||||
Indirect evidence “TELNOR (Teléfonos del Noroeste), empresa líder en servicios de comunicación de telefonía local, larga distancia, proveedora de internet, servicios similares y soluciones…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 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, 2026Thanks. The Data Team will review it. | |||||
| 4 | 229 contacts → | ||||
Indirect evidence “Telikom PNG is the leading telecommunications company with a telecommunications system that is among the most modern in the South Pacific region.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 140 contacts → | ||||
Indirect evidence “General info Mobitel telecommunications services PLC Vilharjeva 23, 1537 Ljubljana, Slovenia Tel:+ 386 (0)1 47 22 200 Fax:+ 386 (0)1 47 22 990 EU VAT number: SI64679438…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 96 contacts → | ||||
Indirect evidence “Qwest is a leading provider of voice, video, and data services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 79 contacts → | ||||
Indirect evidence “Michigan-based TelNet Worldwide, Inc.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 76 contacts → | ||||
Indirect evidence “Headquartered in Fort Lee, NJ, Locus Telecommunications is an established, leading provider of long distance, wireless, point-of-sale and carrier services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 74 contacts → | ||||
Indirect evidence “Cloudli is a leading provider of next generation voice, messaging, and data communications solutions for businesses and consumers.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 72 contacts → | ||||
Indirect evidence “Tu operador de Telecomunicaciones” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 67 contacts → | ||||
Indirect evidence “Headquartered in New York City, InterGlobe Communications is a one stop network service provider.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 51 contacts → | ||||
Indirect evidence “Redvoiss fue la primera empresa latinoamericana en ofrecer el servicio de Telefonía por Internet, cuenta con más de una década en el mercado de las telecomunicaciones.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 48 contacts → | ||||
Indirect evidence “SRVR - the leader in International Telecommunications – helps our customers connect with the world.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 45 contacts → | ||||
Indirect evidence “Since 1980, TCI has provided advanced telecommunication, voice, data and networking solutions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 38 contacts → | ||||
Indirect evidence “Big River Communications is a full-service telecommunications provider serving North America for over 25 years, as well as delivering Voice over IP (VoIP) to service providers…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 36 contacts → | ||||
Indirect evidence “Established in 2002, Selectcom Telecom is one of Canada’s leading providers of voice, data and IP telephony solutions.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 27 contacts → | ||||
Indirect evidence “Shree Telecom LLC is a USA Based VoIP company.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 26 contacts → | ||||
Indirect evidence “CornerStone Telephone Company provides business customers with voice and data communications, cloud computing, data center services and hosted IP products, all coupled with…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 25 contacts → | ||||
Indirect evidence “OPTO Group is an Ultimate Communication Solution Provider having its presence in over 36 countries.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 24 contacts → | ||||
Indirect evidence “Mainstream Digital – Communications Solutions for Business Mainstream Digital is a Business Communications solutions provider with over 20 years of telecommunications experience.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 22 contacts → | ||||
Indirect evidence “VoxSun Telecom, Inc.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 22 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 21 contacts → | ||||
Indirect evidence “Televergence has been saving contact centers and other high volume users an average of 30% savings over AT & T and Verizon on toll free (TF)and long distance pricing for over 33…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 20 contacts → | ||||
Indirect evidence “When you choose Southern California Telephone Company for all your communication needs, we will customize a money-saving, worry-free plan for your home or business that covers…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 17 contacts → | ||||
Indirect evidence “UniVoxx provides business telecommunications ranging from business phones to call centers for companies of all sizes and service providers.” Source: RevenueBase Database · checked Sep 21, 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: calling services. 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 services.
- Partial evidence
- Its own public description names part of calling services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name calling services. 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 332 calling services worldwide
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Calling services worldwide at a glance
As of Sep 21, 2026Companies by employee count
Email recency is reported on each country list linked below.
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 services, 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.
- Coverage
- Every country. Country and city lists for calling services are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “calling services”. 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 services), 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 services, and records with no verified work email.
- 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, 994 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 services by location
1 lists · largest firstEvery Calling services list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
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 services, 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 services are there worldwide?
RevenueBase identified 332 calling services worldwide 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?
Ooma, INC, headquartered in Sunnyvale, tops this list with the largest team on record.
Which country has the most calling services?
The United States leads with 100 companies. Every calling services list by country and city is linked on this page.
Which city has the most calling services?
London leads with 8 headquartered companies, followed by New York (8) and Sao Paulo (4).
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 994 verified decision-maker contacts tracked across these 332 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.