Company lists · Data refreshed August 2026
Top 25 Cloud pbx companies based in the United Kingdom
RevenueBase identified 220 cloud pbx companies headquartered in the United Kingdom as of August 2026 and tracks 1,785 professional contacts across them, including 628 with verified work emails and 200 with mobile numbers. London is the largest hub.
This list covers cloud pbx 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 pbx 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 | 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. | |||||
| 7 | 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. | |||||
| 8 | 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. | |||||
| 9 | 29 contacts → | ||||
Indirect evidence “VoiceMailTel is a high tech innovator and service provider of a unified telecommunication solution which effectively integrates PSTN, VoIP, cellular, voicemail into an…” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 10 | 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. | |||||
| 11 | 21 contacts → | ||||
Indirect 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. | |||||
| 12 | 19 contacts → | ||||
Partial evidence “We are an established telecom service provider taking SMEs to the Cloud using our 18 years of experience, superior customer support and competitive pricing.” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 13 | 17 contacts → | ||||
Indirect 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. | |||||
| 14 | 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. | |||||
| 15 | 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. | |||||
| 16 | 15 contacts → | ||||
Indirect evidence “Fusion Communications helps UK businesses take control of their communications set-up, cutting unnecessary costs, removing inflexible contracts, and replacing poor support with a…” 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 | 13 contacts → | ||||
Indirect evidence “SCG Wholesale is at the cutting edge of internet telephony developing and delivering super reliable technologies, applications and features, including Altos, our flagship white…” Source: RevenueBase Database · checked Aug 31, 2026Thanks. The Data Team will review it. | |||||
| 19 | 12 contacts → | ||||
Partial 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 “IP Office Ltd is a leading supplier of business communications and IT services.” 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 → | ||||
Indirect 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 → | ||||
Strong 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. | |||||
| 25 | 9 contacts → | ||||
Indirect evidence “If you feel that your business telephone system no longer meets the needs of your business then why not talk to us?” 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 pbx 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 pbx companies.
- Partial evidence
- Its own public description names part of cloud pbx companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name cloud pbx 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 220 cloud pbx companies based in the United Kingdom
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 628 reachable decision-makers.
Free signup · no credit card
Cloud pbx 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 pbx 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 pbx 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 pbx 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 pbx 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, 628 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 pbx 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 pbx 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 pbx companies are there based in the United Kingdom?
RevenueBase identified 220 cloud pbx 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 pbx companies?
London leads with 46 headquartered companies, followed by Manchester (7) and Leeds (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 628 verified decision-maker contacts tracked across these 220 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.
Ready to reach these companies? Verified emails and direct dials for all 220 cloud pbx companies based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Cloud pbx companies by geography
- Cloud pbx companies based in the United States
- Cloud pbx companies based in Brazil
- Cloud pbx companies based in Canada
- Cloud pbx companies based in Australia
- Cloud pbx companies based in the Netherlands
- Cloud pbx companies based in Spain
- Cloud pbx companies based in Germany
- Cloud pbx companies based in South Africa
- Cloud pbx companies based in France
- Cloud pbx companies based in Belgium
- Cloud pbx companies based in Italy
- Cloud pbx companies based in Sao Paulo, Brazil
Browse the directory
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.