Company lists · Data refreshed September 2026
Top 25 Business phone system providers based in the United Kingdom
RevenueBase identified 586 business phone system providers headquartered in the United Kingdom as of September 2026 and tracks 8,266 professional contacts across them, including 2,791 with verified work emails. London is the largest hub.
This list covers business phone system providers 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 September 19, 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 providers based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,568 contacts → | ||||
Indirect evidence “Gamma Communications is a leading provider of technology-based communication solutions across Europe.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 655 contacts → | ||||
Indirect evidence “Onecom is the UK’s leading business telecoms and cloud communications provider managing over a million services for business customers - delivering communication services and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 170 contacts → | ||||
Indirect evidence “bOnline is UK’s leading provider of VoIP services for micro and small businesses.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 111 contacts → | ||||
Indirect evidence “We provide communication solutions and IT business services to businesses, big and small, to help your business grow.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 97 contacts → | ||||
Indirect evidence “Yo Telecom is an award winning telecommunications provider that specialises in small to medium sized businesses.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 94 contacts → | ||||
Indirect evidence “Yellowcom is a leading B2B telecoms provider based in Glasgow, Belfast and Dublin, delivering smart, cost-effective communication solutions across the UK and Ireland for over 17…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 90 contacts → | ||||
Partial evidence “Made for businesses of all sizes, Bicom Systems revolutionizes communications by providing PBXware, the world's most unified turnkey open standards hosted telephony platform, plus…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 85 contacts → | ||||
Indirect 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 Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 75 contacts → | ||||
Indirect evidence “Contact an expert now: 0800 9 77 88 99 Specialists in providing businesses with telecoms, data and energy since 1989.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 67 contacts → | ||||
Indirect evidence “Telappliant is an award-winning VoIP and cloud communications provider.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 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 Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 56 contacts → | ||||
Indirect evidence “Established in 1995, Cellular Solutions NE, now part of Communications Plus, is a trusted business telecoms provider supporting organisations across the North East and throughout…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 52 contacts → | ||||
Indirect evidence “Communications Plus is an award-winning UK business telecoms provider, helping organisations across the UK improve the way they communicate, connect and work.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 46 contacts → | ||||
Indirect evidence “Citycom is one of the UK’s leading providers of business telecoms solutions, offering mobile, fixed and cloud services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 44 contacts → | ||||
Indirect evidence “We help UK companies cut costs, stay connected, and scale smarter - with VoIP, mobile and broadband solutions that actually work.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 43 contacts → | ||||
Indirect evidence “The Simplicity Group specialise in fully managed communications and technology solutions for businesses throughout the UK and Ireland.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 43 contacts → | ||||
Indirect evidence “Xinix is UK’s leading cloud-based unified communication provider making persistent efforts towards modernizing business communications.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 37 contacts → | ||||
Indirect evidence “Forever Group is a specialist provider of Business Telecommunications and IT solutions, based in Worcestershire.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 34 contacts → | ||||
Indirect evidence “We are an industry leading provider of Hosted Telephony, Mobile, IT and Connectivity solutions to businesses across the UK.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 32 contacts → | ||||
Indirect evidence “At Lister Unified Communications we understand that everyone’s business telephone requirements are different.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 32 contacts → | ||||
Indirect evidence “Clarity Telecom is Northern Ireland's leading alternative to BT.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 30 contacts → | ||||
Indirect evidence “Silver Lining's unified communications and converged networks offer improved efficiency, reduce running costs and are designed with the flexibility to easily upgrade as your…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 29 contacts → | ||||
Indirect evidence “Comms Connect is an award-winning UK provider of business communications, connectivity and energy solutions, helping organisations stay connected, productive and competitive.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 26 contacts → | ||||
Indirect evidence “Welcome to Radius Connect Solutions.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 24 contacts → | ||||
Indirect evidence “Best 4 Business Communications is a company established on the trust and reliability expected by our customers.” Source: RevenueBase Database · checked Sep 19, 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 providers. 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 providers.
- Partial evidence
- Its own public description names part of business phone system providers, 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 providers. 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 586 business phone system providers based in the United Kingdom
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Business phone system providers based in the United Kingdom at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 586 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 providers, 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 “business phone system providers”. 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 providers), 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 providers, 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, 2,791 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 19, 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.
Business phone system providers by metro
- Business phone system providers in London85
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 providers, 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 providers are there based in the United Kingdom?
RevenueBase identified 586 business phone system providers headquartered in the United Kingdom 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?
GAMMA, headquartered in London, tops this list with the largest team on record.
Which city has the most business phone system providers?
London leads with 85 headquartered companies, followed by Manchester (17) and Birmingham (13).
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 2,791 verified decision-maker contacts tracked across these 586 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 19, 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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