Company lists · Data refreshed September 2026

Top 25 Merger acquisition law firms based in London, United Kingdom

RevenueBase identified 157 merger acquisition law firms headquartered in London, United Kingdom as of September 2026 and tracks 3,957 professional contacts across them, including 1,924 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers merger acquisition law 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 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
157Companies
3,957Contacts tracked
1,924Verified emails
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The 25 largest merger acquisition law firms based in London, United Kingdom

Ranked by team size
Top 25 of 157 merger acquisition law firms 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 merger acquisition law firms: 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
1Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261,001-5,0001,951 contacts →

Partial evidence

“Slaughter and May is regarded as one of the most prestigious law firms in the world.”

Source: RevenueBase Database · checked Sep 28, 2026
2Partial evidenceLondon, United KingdomHQ checked Sep 28, 2026201-500460 contacts →

Partial evidence

“We are a London based, full-service law firm, specialising in providing straightforward advice to ambitious clients ranging from entrepreneurial businesses, family offices and…”

Source: RevenueBase Database · checked Sep 28, 2026
3Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261,001-5,000362 contacts →

Indirect evidence

“Berwin Leighton Paisner and Bryan Cave have combined to form Bryan Cave Leighton Paisner LLP.”

Source: RevenueBase Database · checked Sep 28, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-200114 contacts →

Indirect evidence

“Marriott Harrison is a legal transactional and advisory firm, best known for its market-leading work alongside insightful investors and ambitious companies who build, evolve, and…”

Source: RevenueBase Database · checked Sep 28, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5079 contacts →

Indirect evidence

“We are SI Global.”

Source: RevenueBase Database · checked Sep 28, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20053 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
7Partial evidenceLondon, United KingdomHQ checked Sep 28, 202651-20045 contacts →

Partial evidence

“Rosling King is a rapidly growing UK-based law firm specialising in serving the needs of financial institutions and the real estate, private equity and construction sectors.”

Source: RevenueBase Database · checked Sep 28, 2026
8Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5044 contacts →

Indirect evidence

“LegalEdge is a practical, affordable legal solution for growing companies.”

Source: RevenueBase Database · checked Sep 28, 2026
9Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5036 contacts →

Partial evidence

“London City Law Firm.”

Source: RevenueBase Database · checked Sep 28, 2026
10Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5027 contacts →

Partial evidence

“Mayer Brown is a distinctively global law firm, uniquely positioned to advise the world’s leading companies and financial institutions on their most complex deals and disputes.”

Source: RevenueBase Database · checked Sep 28, 2026
11Strong evidenceLondon, United KingdomHQ checked Sep 28, 2026201-50027 contacts →

Strong evidence

“City of London practice Royds LLP and regional law firm Withy King LLP officially merged on 1 September 2016.”

Source: RevenueBase Database · checked Sep 28, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5018 contacts →

Partial evidence

“We’re a law firm with decades of experience in advising on the full fundraising, investment and exit lifecycle, delivering sensible and commercial insight, without the…”

Source: RevenueBase Database · checked Sep 28, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5016 contacts →

Partial evidence

“XYZ LAW is a legal business, transforming legal services through our people for our clients.”

Source: RevenueBase Database · checked Sep 28, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5015 contacts →

Indirect evidence

“LAVA is an M&A advisory firm with a difference.”

Source: RevenueBase Database · checked Sep 28, 2026
15Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5015 contacts →

Partial evidence

“Established in 2009, Karam, Missick & Traube LLP Solicitors is a full-service law firm in the heart of London specialising in corporate matters and dispute resolution with a…”

Source: RevenueBase Database · checked Sep 28, 2026
16Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5014 contacts →

Partial evidence

“Located in the heart of London’s West End, we are an innovative law firm that personalises our engagements to deliver a tailored and reliable service to our clients.”

Source: RevenueBase Database · checked Sep 28, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 28, 20261,001-5,00013 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 28, 2026
18Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261-1012 contacts →

Partial evidence

“Lewis Mathys Emmerson LLP is a law firm providing first class legal solutions with unequalled client care.”

Source: RevenueBase Database · checked Sep 28, 2026
19Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5012 contacts →

Partial evidence

“Barnes Law operates from Mayfair, where precision meets purpose.”

Source: RevenueBase Database · checked Sep 28, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5011 contacts →

Indirect evidence

“Legal counsel for founders and businesses building what’s next.”

Source: RevenueBase Database · checked Sep 28, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5011 contacts →

Partial evidence

“Costigan King is a full service commercial law firm with offices in the City of London and New York.”

Source: RevenueBase Database · checked Sep 28, 2026
22Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5011 contacts →

Indirect evidence

“Lu Oliphant is the boutique London legal firm with a global reach.”

Source: RevenueBase Database · checked Sep 28, 2026
23Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5010 contacts →

Partial evidence

“We are pleased to announce the merger of Axiom DWFM and Philip Ross Solicitors.”

Source: RevenueBase Database · checked Sep 28, 2026
24Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261-1010 contacts →

Partial evidence

“Bamboo builds and buys law practices, brands and firms.”

Source: RevenueBase Database · checked Sep 28, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-509 contacts →

Indirect evidence

“No one should question that success in M&A is about making the optimal deal.”

Source: RevenueBase Database · checked Sep 28, 2026

Showing 25 of 157 merger acquisition law firms based in London, United Kingdom

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Merger acquisition law firms based in London, United Kingdom at a glance

As of Sep 28, 2026
48.6%Verified-email coverage
25.2Average contacts per company
1-10Median size (employees)
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
102
11-50
35
51-200
10
201-500
3
501-1,000
1
1,001-5,000
5

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 157 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 merger acquisition law 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 “merger acquisition law 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 merger acquisition law 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 merger acquisition law 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, 1,924 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 merger acquisition law 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 merger acquisition law firms are there based in London, United Kingdom?

RevenueBase identified 157 merger acquisition law 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?

Slaughter And MAY, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most merger acquisition law firms?

London leads the United Kingdom with 157 headquartered companies, followed by Bristol (10) and Glasgow (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 1,924 verified decision-maker contacts tracked across these 157 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.

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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.