Company lists · Data refreshed August 2026
Top 25 Cloud phone system companies based in the United Kingdom
RevenueBase identified 181 cloud phone system companies headquartered in the United Kingdom as of August 2026 and tracks 1,744 professional contacts across them, including 610 with verified work emails and 188 with mobile numbers. London is the largest hub.
This list covers cloud phone system companies headquartered in the United Kingdom, 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 August 31, 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 cloud phone system companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 226 contacts → | ||||
Partial evidence “Since 2002, CallTower has been at the forefront of transforming global communication, emerging as a leader in enterprise-class cloud communication, collaboration, and CX solutions.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 2 | 172 contacts → | ||||
Indirect evidence “bOnline is UK’s leading provider of VoIP services for micro and small businesses.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 3 | 85 contacts → | ||||
Partial evidence “Gradwell Communications Ltd are a leading cloud communications solutions provider with a focus on small to medium-sized businesses (SMEs).” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 4 | 84 contacts → | ||||
Indirect evidence “Sipcom exists to make you the hero of your business narrative by turning complexity into clarity.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 5 | 67 contacts → | ||||
Partial evidence “Telappliant is an award-winning VoIP and cloud communications provider.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 6 | 61 contacts → | ||||
Indirect evidence “We’re a leading unified communications provider supplying over 2 million users with the technology they need to work their magic.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 7 | 60 contacts → | ||||
Indirect evidence “Nebula is a leading SaaS provider of workplace communications software, delivering powerful, secure, and adaptable solutions and applications for voice, messaging, customer…” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 8 | 55 contacts → | ||||
Partial evidence “We have over 20 years' experience of working to deliver best of breed cloud telephony solutions to B2B clients.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 9 | 44 contacts → | ||||
Partial evidence “Microtalk: Global Communications Made Simple For over 15 years, Microtalk has delivered reliable voice, messaging, and cloud communications to businesses worldwide.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 10 | 35 contacts → | ||||
Partial evidence “As the UK and Ireland’s longest serving trusted advisor to the Contact Centre industry, SVL has grown to become a leading provider of unified cloud communications and telephony…” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 11 | 32 contacts → | ||||
Indirect evidence “At Lister Unified Communications we understand that everyone’s business telephone requirements are different.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 12 | 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 Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 13 | 21 contacts → | ||||
Strong evidence “Wavetel is one of the top VoIP Phone System and Telecom Services Providers in the UK.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 14 | 17 contacts → | ||||
Strong evidence “VoIPstudio is a complete business phone system and scalable call center with small business pricing.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 15 | 15 contacts → | ||||
Partial evidence “VTSL Ltd is a leading cloud communications company in the UK & Ireland.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 16 | 15 contacts → | ||||
Indirect evidence “ElemenTel are a leading provider of next generation voice over internet (VoIP) telephony solutions to businesses of all types and sizes.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 17 | 13 contacts → | ||||
Partial evidence “British based Splicecom is the Channel focussed Voice Solution provider offering enhanced voice services deployed in the cloud, on–premise or any blend of the two.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 18 | 12 contacts → | ||||
Indirect evidence “At Connect Comms we are committed to supplying all our customers with a first-class service from start to finish for no extra expense.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 19 | 12 contacts → | ||||
Strong evidence “CLOUD TELEPHONE SYSTEM The VoIP Shop is a leading provider of business VoIP phone systems, offering reliable and affordable solutions for small and medium-sized enterprises.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 20 | 12 contacts → | ||||
Indirect evidence “Winning and keeping customers is a challenge for every business.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 21 | 11 contacts → | ||||
Indirect evidence “At Blue Portal, we take the hassle out of business telecoms by offering everything you need under one roof.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 22 | 10 contacts → | ||||
Indirect evidence “Boom brings together the best of unified communications, software as a service and deep analytics to power businesses of all sizes” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 23 | 10 contacts → | ||||
Strong evidence “in2tel provides reliable and feature-rich business VoIP through phone lines, phone systems, and contact centre solutions.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 24 | 10 contacts → | ||||
Indirect evidence “Nexus IP have been providing business telephony nationwide for over 30 years.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 25 | 10 contacts → | ||||
Partial evidence “The Real PBX is a leading provider of unified cloud communication services to consumers and businesses.” Source: RevenueBase Database · checked Aug 31, 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: cloud phone system 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 cloud phone system companies.
- Partial evidence
- Its own public description names part of cloud phone system companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name cloud phone system 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 181 cloud phone system companies based in the United Kingdom
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Cloud phone system companies based in the United Kingdom at a glance
As of Aug 31, 2026Companies by employee count
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 cloud phone system 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 Kingdom whose own description of what they do matches “cloud phone system 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 cloud phone system 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 cloud phone system companies, and records with no verified work email. Companies headquartered outside United Kingdom 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, 610 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 August 31, 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.
Cloud phone system 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 cloud phone system 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 cloud phone system companies are there based in the United Kingdom?
RevenueBase identified 181 cloud phone system companies headquartered in the United Kingdom as of August 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?
Calltower, headquartered in London, tops this list with the largest team on record.
Which city has the most cloud phone system companies?
London leads with 39 headquartered companies, followed by Manchester (6) and Leicester (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 610 verified decision-maker contacts tracked across these 181 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on August 31, 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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