Company lists · Data refreshed September 2026
Top 25 Customer service consulting firms based in London, United Kingdom
RevenueBase identified 867 customer service consulting firms headquartered in London, United Kingdom as of September 2026 and tracks 7,662 professional contacts across them, including 2,219 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers customer service consulting firms 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 24, 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 customer service consulting firms based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 569 contacts → | ||||
Partial evidence “Vertex is a leader in BPO and Customer Management Outsourcing, serving over 200 clients worldwide across many sectors.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 2 | 302 contacts → | ||||
Partial evidence “Cartesian is a specialist consulting firm focused on the global telecommunications, media, and technology industries and is now part of Bounteous, an AI services firm helping…” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 3 | 275 contacts → | ||||
Partial evidence “An award-winning global consulting firm working with clients across a diverse range of markets, industries and geographies.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 4 | 139 contacts → | ||||
Indirect evidence “We believe that change is an opportunity to thrive.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 5 | 96 contacts → | ||||
Partial evidence “We’re service communication experts – using a mix of science, creativity and service know-how to improve how you talk with your customers through all channels and media, from…” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 6 | 85 contacts → | ||||
Indirect evidence “Growth Hub embeds operational teams inside professional services firms.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 7 | 76 contacts → | ||||
Partial evidence “We’re a specialist, management consultancy, focusing on; Customer Experience, Operational Excellence and Change Delivery, dedicated to helping our clients create real, positive…” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 8 | 74 contacts → | ||||
Indirect evidence “Whether complex transformation is required across your business or you are seeking support with a small project, we are here to help.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 9 | 72 contacts → | ||||
Indirect evidence “Welcome to Acuity, an award-winning front of house service provider.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 10 | 69 contacts → | ||||
Indirect evidence “In complex transformation programmes, risk, regulation, financial crime, data, technology and operations no longer sit in separate silos.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 11 | 66 contacts → | ||||
Indirect evidence “Tecsa is a specialist retail loyalty and analytics consultancy founded and led by former retail executives who built and ran major loyalty programmes, including Nectar, Holland &…” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 12 | 63 contacts → | ||||
Indirect evidence “Business Systems is a trusted transformation partner with over 35 years of experience helping CX teams and contact centres become smarter, faster and more compliant.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 13 | 59 contacts → | ||||
Indirect evidence “Consult us for.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 14 | 51 contacts → | ||||
Partial evidence “For nearly 4 decades, we have worked with some of the world’s best brands to design and enable great customer experiences.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 15 | 49 contacts → | ||||
Partial evidence “Since we’ve helped ambitious leaders and organisations create true customer-led success.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 16 | 49 contacts → | ||||
Indirect evidence “Designhouse is where strategy takes shape.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 17 | 49 contacts → | ||||
Partial evidence “Unlocking the extraordinary is our raison d’être at White Page International (WPI), a trailblazing consulting firm that dares to redefine the realm of possibility.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 18 | 38 contacts → | ||||
Indirect evidence “At Regency Grove we pride ourselves on providing each client with an exceptional standard of service to suit their specific needs and requirements.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 19 | 38 contacts → | ||||
Indirect evidence “We’re the full-service HR consultancy that synchronises seamlessly with your business.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 20 | 38 contacts → | ||||
Indirect evidence “Inforom Consultancy Services helps companies expand, strengthen and launch Internationally.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 21 | 35 contacts → | ||||
Indirect evidence “Market Intelligence International (Marketii) is a trusted advisor to the world’s leading organizations in technology, medical devices, and consumer products.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 22 | 34 contacts → | ||||
Partial evidence “Customer Acquisition seems to be the end goal of so much global marketing spend, yet the complexity of all the moving parts is often overlooked.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 23 | 33 contacts → | ||||
Partial evidence “KPMG Nunwood specialises in customer experience improvement.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 24 | 32 contacts → | ||||
Partial evidence “StableLogic is a technology consultancy specialising in customer contact, networking, software development and cloud expertise.” Source: RevenueBase Database · checked Sep 24, 2026Thanks. The Data Team will review it. | |||||
| 25 | 28 contacts → | ||||
Partial evidence “Our customer service outsourcing and software solutions create happier customers, happier customer service agents, and save you money.” Source: RevenueBase Database · checked Sep 24, 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: customer service consulting firms. 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 customer service consulting firms.
- Partial evidence
- Its own public description names part of customer service consulting firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name customer service consulting firms. 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 867 customer service consulting firms based in London, United Kingdom
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Customer service consulting firms based in London, United Kingdom at a glance
As of Sep 24, 2026Companies by employee count
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 867 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 customer service consulting firms, 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 “customer service consulting firms”. 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 customer service consulting firms), 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 customer service consulting firms, 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, 2,219 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 24, 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.
Customer service consulting firms by metro in the United Kingdom
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 customer service consulting firms, 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 customer service consulting firms are there based in London, United Kingdom?
RevenueBase identified 867 customer service consulting firms 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?
Vertex Data Science, headquartered in London, tops this list with the largest team on record.
Which city in the United Kingdom has the most customer service consulting firms?
London leads the United Kingdom with 867 headquartered companies, followed by Manchester (59) and Bristol (30).
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 2,219 verified decision-maker contacts tracked across these 867 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 24, 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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