Company lists · Data refreshed September 2026

Top 25 International tax services based in the United Kingdom

RevenueBase identified 362 international tax services headquartered in the United Kingdom as of September 2026 and tracks 5,884 professional contacts across them, including 1,574 with verified work emails. London is the largest hub.

This list covers international tax services 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 20, 2026 86% judged on-target in blind review
362Companies
5,884Contacts tracked
1,574Verified emails
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The 25 largest international tax services based in the United Kingdom

Ranked by team size
Top 25 of 362 international tax services based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 20, 2026. RevenueBase Smart Search rates how each company's information relates to international tax services: 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 evidenceBrighton, United KingdomHQ checked Sep 20, 2026n/a2,042 contacts →

Indirect evidence

“A traditional general practice, with a twist.”

Source: RevenueBase Database · checked Sep 20, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 20, 2026501-1,0001,151 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, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 20, 202610001+177 contacts →

Partial evidence

“Thoughtfully structuring and managing your tax affairs is more important than ever.”

Source: RevenueBase Database · checked Sep 20, 2026
4Partial evidenceLondon, United KingdomHQ checked Sep 20, 202611-50101 contacts →

Partial evidence

“Welcome to AOG, your esteemed accounting and tax partner, serving SMEs and high-net-worth individuals in the UK and abroad.”

Source: RevenueBase Database · checked Sep 20, 2026
5Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20085 contacts →

Partial evidence

“We are a team of helpful tax and financial planning experts, here to listen, understand your needs and circumstances and make all aspects of dealing with your finances simple…”

Source: RevenueBase Database · checked Sep 20, 2026
6Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20075 contacts →

Partial evidence

“USTAXFS are the largest independent tax accounting firm in the UK & Europe specialising in US tax, including the complex specialism of US and UK cross-border tax planning.”

Source: RevenueBase Database · checked Sep 20, 2026
7Indirect evidenceLondon, United KingdomHQ checked Sep 20, 202651-20062 contacts →

Indirect evidence

“Fusion is a multi-disciplinary consulting firm that offers 360 degree advisory services and end-to-end solutions for private individuals and fast growth businesses.”

Source: RevenueBase Database · checked Sep 20, 2026
8Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20051 contacts →

Partial evidence

“The Tax Advisory Partnership is a young and vibrant London-based organisation, which brings together a wealth of wide ranging experience and expertise in all areas of UK and US…”

Source: RevenueBase Database · checked Sep 20, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 20, 202611-5048 contacts →

Indirect evidence

“We provide accounting, business advice and assistance for businesses investing abroad.”

Source: RevenueBase Database · checked Sep 20, 2026
10Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20042 contacts →

Partial evidence

“Diacron Group provides accounting, tax and corporate services.”

Source: RevenueBase Database · checked Sep 20, 2026
11Partial evidenceNewport, United KingdomHQ checked Sep 20, 202651-20038 contacts →

Partial evidence

International expansion should not mean managing a different accountant, lawyer, payroll provider and HR adviser in every country.”

Source: RevenueBase Database · checked Sep 20, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20037 contacts →

Partial evidence

“TBA Global (also known as TB Accountants) is your trusted partner for accounting and tax solutions!”

Source: RevenueBase Database · checked Sep 20, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 20, 202611-5031 contacts →

Partial evidence

“As specialists in UK, US and Expatriate Tax, we provide unique tax advisory and compliance services that assist both individuals and companies.”

Source: RevenueBase Database · checked Sep 20, 2026
14Strong evidenceManchester, United KingdomHQ checked Sep 20, 202611-5031 contacts →

Strong evidence

“Thomas & Co International is a multi-award winning accounting and tax advisory firm helping business owners protect their assets, reduce their taxes, and build real, lasting…”

Source: RevenueBase Database · checked Sep 20, 2026
15Partial evidenceEllesmere Port, United KingdomHQ checked Sep 20, 202651-20029 contacts →

Partial evidence

“Alexander Beard are specialist International Financial Advisers.”

Source: RevenueBase Database · checked Sep 20, 2026
16Partial evidenceLondon, United KingdomHQ checked Sep 20, 202611-5028 contacts →

Partial evidence

“WTT provides experienced tax advisers, legal experts and finance professionals.”

Source: RevenueBase Database · checked Sep 20, 2026
17Partial evidenceLondon, United KingdomHQ checked Sep 20, 20261-1026 contacts →

Partial evidence

“not all accountants are tax specialists and not all tax consultants are accountants" At IBISS & CO we appreciate the value of working together as a team.”

Source: RevenueBase Database · checked Sep 20, 2026
18Indirect evidenceMilton Keynes, United KingdomHQ checked Sep 20, 202651-20023 contacts →

Indirect evidence

“Xcelentra specializes in accounting, taxation, payroll, finance, and immigration services across the UK and Europe.”

Source: RevenueBase Database · checked Sep 20, 2026
19Partial evidenceLondon, United KingdomHQ checked Sep 20, 202651-20021 contacts →

Partial evidence

“KNAV is a dynamic global accounting and consulting firm, offering a comprehensive range of services including accounting, assurance, taxation, international transfer pricing…”

Source: RevenueBase Database · checked Sep 20, 2026
20Indirect evidenceSheffield, United KingdomHQ checked Sep 20, 202611-5021 contacts →

Indirect evidence

“Our mission is to advise, guide and support our clients to ensure they become as successful as all their hard work should make them.”

Source: RevenueBase Database · checked Sep 20, 2026
21Partial evidenceCoventry, United KingdomHQ checked Sep 20, 202611-5019 contacts →

Partial evidence

“SGD are a leading firm of accountants and tax advisers offering bespoke tax and accounting advice.”

Source: RevenueBase Database · checked Sep 20, 2026
22Indirect evidenceFinchley, United KingdomHQ checked Sep 20, 202651-20019 contacts →

Indirect evidence

“We provide experienced and specialist staff committed to the success of each client's business, always focusing on our working principle of adding value to a client's business…”

Source: RevenueBase Database · checked Sep 20, 2026
23Indirect evidencePreston, United KingdomHQ checked Sep 20, 2026201-50018 contacts →

Indirect evidence

“Why MHA Moore and Smalley?”

Source: RevenueBase Database · checked Sep 20, 2026
24Partial evidenceLondon, United KingdomHQ checked Sep 20, 202611-5018 contacts →

Partial evidence

“K3 Advantage is a trusted advisor focusing on Transactions, Tax Advisory and Strategy.”

Source: RevenueBase Database · checked Sep 20, 2026
25Partial evidenceHolborn, United KingdomHQ checked Sep 20, 202611-5018 contacts →

Partial evidence

“Churchill Tax Advisers would love to help you understand how our services can save you money with the HMRC.”

Source: RevenueBase Database · checked Sep 20, 2026

Showing 25 of 362 international tax services based in the United Kingdom

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International tax services based in the United Kingdom at a glance

As of Sep 20, 2026
26.8%Verified-email coverage
16.3Average contacts per company
1-10Median size (employees)
45.9%Largest-city concentration · London
Sep 20, 2026Page data refreshed

Companies by employee count

1-10
233
11-50
98
51-200
20
201-500
4
501-1,000
3
10001+
1

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 362 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 international tax services, 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 “international tax services”. 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 international tax services), 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 international tax services, 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, 1,574 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.

International tax services by metro

  • International tax services in London166

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 international tax services, 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 international tax services are there based in the United Kingdom?

RevenueBase identified 362 international tax services 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?

TAX Consultant, headquartered in Brighton, tops this list with the largest team on record.

Which city has the most international tax services?

London leads with 166 headquartered companies, followed by Manchester (11) and Birmingham (9).

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 1,574 verified decision-maker contacts tracked across these 362 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.