Company lists · Data refreshed September 2026

Top 18 Enterprise voice consultants based in London, United Kingdom

RevenueBase identified 52 enterprise voice consultants headquartered in London, United Kingdom as of September 2026 and tracks 509 professional contacts across them, including 129 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers enterprise voice consultants headquartered in London, 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 28, 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 28, 2026 86% judged on-target in blind review
52Companies
509Contacts tracked
129Verified emails
Explore this list → Free signup · no credit card · 500 free credits

The 18 largest enterprise voice consultants based in London, United Kingdom

Ranked by team size
Top 18 of 52 enterprise voice consultants based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to enterprise voice consultants: 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 28, 202610001+120 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20067 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
3Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20046 contacts →

Indirect evidence

“The Symity team are a group of passionate Microsoft Teams advocates who are dedicated to changing the way people work.”

Source: RevenueBase Database · checked Sep 28, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5012 contacts →

Indirect evidence

“Winning and keeping customers is a challenge for every business.”

Source: RevenueBase Database · checked Sep 28, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5010 contacts →

Indirect evidence

“Nexus IP have been providing business telephony nationwide for over 30 years.”

Source: RevenueBase Database · checked Sep 28, 2026
6Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-508 contacts →

Partial evidence

“Who we are - Established in 2004 CSL Integration is a technology solutions Company providing tailored voice, data and video services that add value and improve the way Companies…”

Source: RevenueBase Database · checked Sep 28, 2026
7Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-507 contacts →

Indirect evidence

“Interact Technology has extensive experience derived from over 20 years in providing business to business communications.”

Source: RevenueBase Database · checked Sep 28, 2026
8Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261-106 contacts →

Partial evidence

“Pentima: Your Trusted Advisor in WAN & Telecommunications, Cloud & Security Solutions Pentima is a renowned consultancy specialising in the WAN & telecommunications, Cloud &…”

Source: RevenueBase Database · checked Sep 28, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-506 contacts →

Indirect evidence

“At ZiAAS, we're passionate about harnessing the power of technology to transform businesses and streamline operations.”

Source: RevenueBase Database · checked Sep 28, 2026
10Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-104 contacts →

Indirect evidence

“GIVE YOUR CLIENTS THE CUSTOMER EXPERIENCE THEY DESERVE!”

Source: RevenueBase Database · checked Sep 28, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-104 contacts →

Indirect evidence

“Voicelinx are experts in VOIP telecoms.”

Source: RevenueBase Database · checked Sep 28, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261-104 contacts →

Partial evidence

“Soniza is a truly independent telecoms consultancy.”

Source: RevenueBase Database · checked Sep 28, 2026
13Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-2003 contacts →

Indirect evidence

“Broadgate is the amalgamation of Acorn Networks Services and Sure Communications.”

Source: RevenueBase Database · checked Sep 28, 2026
14Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261-102 contacts →

Partial evidence

“BlackBox Technologies provide IT consultancy services to the SME sector ranging from Auditing, Cloud Evaluation Assessment, High level project design implementation and strategic…”

Source: RevenueBase Database · checked Sep 28, 2026
15Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-101 contacts →

Indirect evidence

“Your Audio Visual Partner.”

Source: RevenueBase Database · checked Sep 28, 2026
16Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-101 contacts →

Indirect evidence

“Empowering Businesses with Tailored Cloud Solutions: The Unique Role of 186Kloud The Unique Role of 186Kloud 186Kloud distinguishes itself by acting as a trusted advisor, helping…”

Source: RevenueBase Database · checked Sep 28, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-101 contacts →

Indirect evidence

“Let’s start with the WHY… We help channel partners leverage opportunities created by new technologies and business platforms through consultative and market intelligence services.”

Source: RevenueBase Database · checked Sep 28, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261-101 contacts →

Indirect evidence

“Since our inception Circle have been successfully delivering reliable and cost effective Unified Communications solutions to clients across a variety of sectors and specialisms.”

Source: RevenueBase Database · checked Sep 28, 2026

Showing 18 of 52 enterprise voice consultants based in London, United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 129 reachable decision-makers.

Free signup · no credit card

View the full list →

Enterprise voice consultants based in London, United Kingdom at a glance

As of Sep 28, 2026
25.3%Verified-email coverage
9.8Average contacts per company
11-50Median size (employees)
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
22
11-50
19
51-200
7
201-500
1
10001+
1

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 52 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 enterprise voice consultants, 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 London, United Kingdom whose own description of what they do matches “enterprise voice consultants”. 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 enterprise voice consultants), 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 enterprise voice consultants, and records with no verified work email. Companies headquartered outside London 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, 129 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 28, 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.

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 enterprise voice consultants, 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 enterprise voice consultants are there based in London, United Kingdom?

RevenueBase identified 52 enterprise voice consultants headquartered in London, 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 in the United Kingdom has the most enterprise voice consultants?

London leads the United Kingdom with 52 headquartered companies, followed by Leeds (5) and Sheffield (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 129 verified decision-maker contacts tracked across these 52 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 28, 2026.

Ready to reach these companies? Verified emails and direct dials for all 52 enterprise voice consultants based in London, United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

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.