Company lists · Data refreshed September 2026
Top 25 Professional service firms based in the United Kingdom
RevenueBase identified 440 professional service firms headquartered in the United Kingdom as of September 2026 and tracks 9,104 professional contacts across them, including 3,911 with verified work emails. London is the largest hub.
This list covers professional service firms 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 20, 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 professional service firms based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 1,395 contacts → | ||||
Indirect evidence “Crowe UK is a leading audit, tax, advisory and consulting firm with a national presence to complement our international reach.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 1,151 contacts → | ||||
Indirect evidence “At Moore Kingston Smith, we believe in the potential of people to make a positive impact, fuelled by the power of genuine understanding.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 702 contacts → | ||||
Indirect evidence “We are a fast-growing firm of accountants and business advisers based in London’s Canary Wharf, Leeds and in Manchester.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 602 contacts → | ||||
Indirect evidence “We guide our clients, colleagues and communities to a brighter future.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 505 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 379 contacts → | ||||
Indirect evidence “Welcome to the new era of accountancy.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 258 contacts → | ||||
Indirect evidence “Ellisons is one of the region’s oldest, most established and fastest growing firms.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 171 contacts → | ||||
Strong evidence “Our pioneering integrated approach to professional services cuts through the complicated layers of the legal and accountancy world to give you straightforward joined-up advice and…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 143 contacts → | ||||
Indirect evidence “Ballards LLP is an integrated advisory firm with offices in Birmingham, Worcester, and Droitwich, helping businesses and private client make faster, better-informed decisions.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 131 contacts → | ||||
Indirect evidence “We are a multi-service, innovative law firm based in Hertfordshire, known for delivering clients outstanding service and our award winning legal advice.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 97 contacts → | ||||
Strong evidence “K3 Capital Group is a professional services firm providing advisory services to SMEs throughout the UK and overseas.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 93 contacts → | ||||
Indirect evidence “BDO NI specialises in helping businesses, whether start-ups or multinationals, to grow.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 92 contacts → | ||||
Strong evidence “Baker Tilly is a leading professional services firm which provides a range of accounting and advisory services to a broad spectrum of clients, from public companies to…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 88 contacts → | ||||
Strong evidence “Founded in 2001 by lawyers, Global BPO provides bespoke legal and business services to law firms, professional service organisations and other businesses.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 82 contacts → | ||||
Strong evidence “Beavis Morgan is part of the Kinbrook Group, a people-first accounting, wealth management, legal and professional advisory services group.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 73 contacts → | ||||
Indirect evidence “MG Group is a multi-disciplinary practice providing accounting, tax, audit, legal and business consulting services.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 71 contacts → | ||||
Indirect evidence “Sharma & Co operates from offices in Birmingham, London and Manchester delivering practical and cost effective advice.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 70 contacts → | ||||
Indirect evidence “HWB is a leading firm of Chartered Accountants offering the depth of resource and specialist skills of a national practice.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 53 contacts → | ||||
Strong evidence “Adams & Moore is a professional firm of Auditors, Tax and Professional Advisors offering a comprehensive range of accounting, compliance, financial and business advisory services…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 52 contacts → | ||||
Indirect evidence “Our integrated approach brings together accountancy and financial planning to maximise your financial performance.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 47 contacts → | ||||
Indirect evidence “At Moore, our purpose is to help people thrive – our clients, our people and the communities they live and work in.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 47 contacts → | ||||
Indirect evidence “Goldschmidt & Howland was established way back in the 19th century and for a company with such a long history, our attitudes are surprisingly modern.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 42 contacts → | ||||
Indirect evidence “Established 40 years ago, Tunbridge Wells-based CooperBurnett is focused on building long-term relationships with our clients, based around excellent communication and exceptional…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 39 contacts → | ||||
Indirect evidence “Glazers is a well-established and progressive firm of accountants based in North West London.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 37 contacts → | ||||
Indirect evidence “Rödl & Partner – The agile caring partner for Mittelstand shaped world market leaders As attorneys, tax advisers, management and IT consultants and auditors, we are present with…” Source: RevenueBase Database · checked Sep 20, 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: professional service 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 professional service firms.
- Partial evidence
- Its own public description names part of professional service firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name professional service 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 440 professional service firms based in the United Kingdom
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Professional service firms based in the United Kingdom at a glance
As of Sep 20, 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 440 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 professional service 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 the United Kingdom whose own description of what they do matches “professional service 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 professional service 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 professional service firms, 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, 3,911 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 20, 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.
Professional service firms by metro
- Professional service firms in London153
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 professional service 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 professional service firms are there based in the United Kingdom?
RevenueBase identified 440 professional service firms 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?
Crowe UK, headquartered in London, tops this list with the largest team on record.
Which city has the most professional service firms?
London leads with 153 headquartered companies, followed by Birmingham (11) and Manchester (7).
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 3,911 verified decision-maker contacts tracked across these 440 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 20, 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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