Company lists · Data refreshed September 2026

Top 25 Ucaas platform companies based in the United Kingdom

RevenueBase identified 100 ucaas platform companies headquartered in the United Kingdom as of September 2026 and tracks 1,305 professional contacts across them, including 441 with verified work emails. London is the largest hub.

This list covers ucaas platform 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 September 14, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 14, 2026 86% judged on-target in blind review
100Companies
1,305Contacts tracked
441Verified emails
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The 25 largest ucaas platform companies based in the United Kingdom

Ranked by team size
Top 25 of 100 ucaas platform companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to ucaas platform companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202610001+120 contacts →

Indirect evidence

“The Collaboration and CX solutions offered by NTT Ltd.”

Source: RevenueBase Database · checked Sep 14, 2026
2Partial evidenceLondon, United KingdomHQ checked Sep 14, 202651-20090 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 14, 2026
3Indirect evidenceLondon, United KingdomHQ checked Sep 14, 2026501-1,00086 contacts →

Indirect evidence

“Sipcom exists to make you the hero of your business narrative by turning complexity into clarity.”

Source: RevenueBase Database · checked Sep 14, 2026
4Indirect evidenceBath, United KingdomHQ checked Sep 14, 202651-20085 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 14, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202651-20067 contacts →

Indirect evidence

“Telappliant is an award-winning VoIP and cloud communications provider.”

Source: RevenueBase Database · checked Sep 14, 2026
6Indirect evidenceGuildford, United KingdomHQ checked Sep 14, 202651-20062 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 Sep 14, 2026
7Indirect evidenceBolton, United KingdomHQ checked Sep 14, 202651-20056 contacts →

Indirect evidence

“We have over 20 years' experience of working to deliver best of breed cloud telephony solutions to B2B clients.”

Source: RevenueBase Database · checked Sep 14, 2026
8Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202611-5045 contacts →

Indirect 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 Sep 14, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202611-5043 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 14, 2026
10Indirect evidenceEast Kilbride, United KingdomHQ checked Sep 14, 202611-5036 contacts →

Indirect 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 Sep 14, 2026
11Indirect evidenceSlough, United KingdomHQ checked Sep 14, 202651-20032 contacts →

Indirect evidence

“We are a leading worldwide provider of cloud-based and customer hosted managed visual communication and collaboration services.”

Source: RevenueBase Database · checked Sep 14, 2026
12Indirect evidenceThame, United KingdomHQ checked Sep 14, 202651-20018 contacts →

Indirect evidence

“MeetingZone was set up in 2002 and has operations in the UK, Germany, USA, Nordics and Asia Pacific.”

Source: RevenueBase Database · checked Sep 14, 2026
13Indirect evidencePoole, United KingdomHQ checked Sep 14, 202611-5015 contacts →

Indirect evidence

“Communications Reimagined.”

Source: RevenueBase Database · checked Sep 14, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202611-5015 contacts →

Indirect evidence

“VTSL Ltd is a leading cloud communications company in the UK & Ireland.”

Source: RevenueBase Database · checked Sep 14, 2026
15Indirect evidenceLeicester, United KingdomHQ checked Sep 14, 202611-5013 contacts →

Indirect 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 Sep 14, 2026
16Indirect evidenceLondon, United KingdomHQ checked Sep 14, 202611-5013 contacts →

Indirect evidence

“Since 2006, Elisha Telecom has been at the forefront of innovation in the field of Unified Communications.”

Source: RevenueBase Database · checked Sep 14, 2026
17Partial evidenceAylesbury, United KingdomHQ checked Sep 14, 202611-5012 contacts →

Partial evidence

“Callroute is an award-winning global SaaS platform, built to be the control layer for modern business voice.”

Source: RevenueBase Database · checked Sep 14, 2026
18Indirect evidenceBasingstoke, United KingdomHQ checked Sep 14, 202611-5010 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 Sep 14, 2026
19Indirect evidenceFleet, United KingdomHQ checked Sep 14, 202611-5010 contacts →

Indirect evidence

“With over a decade of experience in the telecommunications and contact centre industry, Support to Win is the trusted outsourcing partner for vendors, carriers, distributors…”

Source: RevenueBase Database · checked Sep 14, 2026
20Indirect evidenceSnodland, United KingdomHQ checked Sep 14, 202611-5010 contacts →

Indirect evidence

“The Real PBX is a leading provider of unified cloud communication services to consumers and businesses.”

Source: RevenueBase Database · checked Sep 14, 2026
21Partial evidenceManchester, United KingdomHQ checked Sep 14, 202611-509 contacts →

Partial evidence

“Dimensions Technologies is a leading independent software vendor and Unified Communications as a Service (UCaaS) provider.”

Source: RevenueBase Database · checked Sep 14, 2026
22Indirect evidenceWatford, United KingdomHQ checked Sep 14, 2026201-5009 contacts →

Indirect evidence

“StarLeaf enables seamless collaboration through intelligently engineered, reliable meeting room systems, superior video conferencing, and secure messaging.”

Source: RevenueBase Database · checked Sep 14, 2026
23Indirect evidenceBelfast, United KingdomHQ checked Sep 14, 202611-508 contacts →

Indirect evidence

“Voxbit is reinventing the business phone by merging the worlds of cloud computing, web services & telecommunications to make collaborating part of the team.”

Source: RevenueBase Database · checked Sep 14, 2026
24Indirect evidenceLeeds, United KingdomHQ checked Sep 14, 202611-508 contacts →

Indirect evidence

“The Technology Group are a managed communications provider, helping businesses and organisations to better communicate with their customers and teams, by embracing voice over IP…”

Source: RevenueBase Database · checked Sep 14, 2026
25Indirect evidenceFareham, United KingdomHQ checked Sep 14, 202611-507 contacts →

Indirect evidence

“sipsynergy is the new standard in reliable, high quality hosted communications and collaboration.”

Source: RevenueBase Database · checked Sep 14, 2026

Showing 25 of 100 ucaas platform 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 441 reachable decision-makers.

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Ucaas platform companies based in the United Kingdom at a glance

As of Sep 14, 2026
33.8%Verified-email coverage
13.1Average contacts per company
11-50Median size (employees)
28.0%Largest-city concentration · London
Sep 14, 2026Page data refreshed

Companies by employee count

1-10
40
11-50
37
51-200
14
201-500
2
501-1,000
2
10001+
2

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 100 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 ucaas platform 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 “ucaas platform 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 ucaas platform 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 ucaas platform 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, 441 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 14, 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.

Ucaas platform companies by metro

  • Ucaas platform companies in London28

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 ucaas platform 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 ucaas platform companies are there based in the United Kingdom?

RevenueBase identified 100 ucaas platform companies 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?

NTT Ltd. Collaboration & CX, headquartered in London, tops this list with the largest team on record.

Which city has the most ucaas platform companies?

London leads with 28 headquartered companies, followed by Birmingham (3) and Manchester (3).

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 441 verified decision-maker contacts tracked across these 100 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 14, 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.