Company lists · Data verified August 2026

Top 25 Cloud communications companies based in London, United Kingdom

Name: Cloud communications companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Verified Aug 28, 2026 69 companies tracked

There are 69 cloud communications companies headquartered in London, United Kingdom (RevenueBase, August 2026). RevenueBase tracks 2,511 professional contacts across them, including 914 with verified work emails and 427 with mobile numbers. London is the largest hub.

This list covers cloud communications companies headquartered in London, United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Data current as of August 28, 2026.

69Companies

2,511Contacts tracked

914Verified emails

427Mobile numbers

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The 25 largest cloud communications companies based in London, United Kingdom

Ranked by team size

Top 25 of 69 cloud communications companies based in London, United Kingdom, ranked by team size, largest first. Data verified Aug 28, 2026. Click a count to unlock that company's people.
#	Company	HQ	Employees	Contacts	Verified emails
1	Kaltura	London	501-1,000	734	386
2	Imimobile Part Of Webex	London	1,001-5,000	436	54
3	Calltower	London	201-500	226	128
4	Synacor	London	201-500	182	81
5	Luware	London	51-200	154	110
6	NTT Ltd. Collaboration & CX	London	10001+	120	15
7	Wavecrest	London	51-200	92	18
8	Sipcom	London	501-1,000	84	28
9	Microtalk	London	11-50	44	9
10	Quickblox	London	11-50	31	14
11	Marlin Communications	London	11-50	22	19
12	Conversant Technology	London	11-50	17	7
13	VTSL	London	11-50	15	9
14	The Technology Group	London	11-50	8	5
15	Purpleuc	London	11-50	7	5
16	Purify Technology LTD	London	1-10	7	4
17	Holler Technology LTD	London	11-50	7	3
18	APALO	London	1-10	7	1
19	ZIAAS	London	11-50	6	2
20	Glemnet LTD	London	1-10	6	2
21	Moore Technology LTD	London	1-10	5	2
22	Sipalto	London	11-50	4	3
23	Voicelinx LTD	London	1-10	4	3
24	Revolution Phones LTD	London	1-10	2	2
25	Exponential-E Limited	London	501-1,000	2	1

Showing 25 of 69 cloud communications companies based in London, United Kingdom

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Cloud communications companies based in London, United Kingdom at a glance

As of Aug 28, 2026

11-50Median size (employees)

LondonLargest hub · 69 HQs

427Contacts with mobile numbers

0Emails re-verified in last 30 days

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

10001+

Cloud communications companies by metro in the United Kingdom

Metro	Companies
Cloud communications companies in London	69
Cloud communications companies in Manchester	6
Cloud communications companies in Poole	5
Cloud communications companies in Leeds	5
Cloud communications companies in Birmingham	4
Cloud communications companies in Nottingham	4
Cloud communications companies in Belfast	3

How this list was built

Source: The RevenueBase company graph: 21.3 million companies and 398.9 million professional contacts resolved from primary sources.
Inclusion: Companies whose own business descriptions match “cloud communications companies”, with match quality audited by blind human judging, and headquartered in London, United Kingdom.
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: Contact records re-verify on a rolling cadence; 0 contacts on this list were re-verified in the last 30 days.
Refresh: Lists are refreshed periodically as the underlying company graph is re-verified. Last verified Aug 28, 2026.

Frequently asked

How many cloud communications companies are there based in London, United Kingdom?

There are 69 cloud communications companies headquartered in London, United Kingdom as of August 2026 (RevenueBase).

What is the largest company on this list?

Kaltura, headquartered in London, tops this list with the largest team on record.

Which city has the most cloud communications companies?

London leads with 69 headquartered companies, followed by Manchester (6) and Poole (5).

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 914 verified decision-maker contacts tracked across these 69 companies.

How current is this list?

The list is refreshed periodically as the underlying company graph is re-verified. It was last verified on August 28, 2026.

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About this data

RevenueBase is a B2B contact data platform. Its company graph covers 21.3 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, the same data that powers RevenueBase's B2B data products and the free research portal.