Company lists · Data refreshed September 2026
Top 25 IT audit firms based in the United Kingdom
RevenueBase identified 101 IT audit firms headquartered in the United Kingdom as of September 2026 and tracks 737 professional contacts across them, including 253 with verified work emails. London is the largest hub.
This list covers IT audit 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 IT audit firms based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 117 contacts → | ||||
Indirect evidence “Relax.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 2 | 31 contacts → | ||||
Partial evidence “SPECIALISTS IN IT SECURITY AND COMPLIANCE Our goal is to help customers define, develop and implement information security and compliance services, no matter what stage of the…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 3 | 26 contacts → | ||||
Partial evidence “Providing internal audit, technology risk assurance and counter fraud services in the North of England.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 4 | 20 contacts → | ||||
Partial evidence “We at CF assist enterprises manage IT risks better.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 5 | 18 contacts → | ||||
Strong evidence “Platformed's AI auditor automates IT and financial audits end-to-end.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 6 | 16 contacts → | ||||
Partial evidence “Specialist internal audit, governance, risk and compliance services provider; helping our clients Improve, Comply and Optimise.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 7 | 13 contacts → | ||||
Partial evidence “Parker Russell is a leading audit firm offering comprehensive services to medium to large corporations, specialising in FCA-regulated environments and stock exchange-listed…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 8 | 13 contacts → | ||||
Indirect evidence “We are registered auditors and have a wide experience in reporting under the Companies Act and the special rules which govern solicitors.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 9 | 12 contacts → | ||||
Indirect evidence “Cyber Guarded is a vendor independent business which provides Cyber Security auditing and testing services.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 10 | 12 contacts → | ||||
Partial evidence “Mills Pyatt a professional Audit & Accounting firm based centrally in the UK, just south of Birmingham.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 11 | 11 contacts → | ||||
Partial evidence “Zenith Audit UK is a specialist audit firm delivering assurance and risk management services to SMEs in the financial services industry and beyond.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 12 | 11 contacts → | ||||
Partial evidence “Cyber Trust | Your security team around your existing IT Cyber Trust is a UK‑based cyber security firm that works alongside your existing IT team or technology provider.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 13 | 10 contacts → | ||||
Partial evidence “When you work with us, you can expect a no-fuss, reliable audit.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 14 | 9 contacts → | ||||
Partial evidence “Corporate IT Systems (CITSL) helps the organisations society depends on most make trust provable.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 15 | 9 contacts → | ||||
Indirect evidence “Cube Partners Limited is a firm of Chartered Accountants and Registered Auditors, regulated by the Institute of Chartered Accountants in England & Wales.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 16 | 8 contacts → | ||||
Partial evidence “360 Forensic deploys in-depth audit expertise combined with proprietary software data solutions to identify missed revenue, tighten IP compliance and flag commercial issues for a…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 17 | 7 contacts → | ||||
Indirect evidence “Through excellent consultancy we protect clients from reputation damage, financial penalties and the operational disruption associated with data incidents and cyberattacks.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 18 | 7 contacts → | ||||
Partial evidence “CyberSRC specialises in 1LoD & 2LoD Operational & IT Risk, Security and Control Management & Transformation through developing, implementing, auditing, risk assessing and managing…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 19 | 7 contacts → | ||||
Indirect evidence “Founded on the belief that auditing can be positive and stress-free, Byrd + Link specialise in partnering with leading regional Accountancy Practices, and supporting commercial…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 20 | 6 contacts → | ||||
Indirect evidence “Ollis & Co is an experienced and proactive firm of Chartered Accountants and Registered Auditors based in Leamington Spa, Warwickshire.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 21 | 6 contacts → | ||||
Indirect evidence “NGS Secure is now NCC Group NCC Group is a leading global information assurance firm, providing freedom from doubt that all critical material is available, protected, and…” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 22 | 5 contacts → | ||||
Partial evidence “At Pronetic, we help businesses reduce the stress of managing IT, compliance, and security.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 23 | 5 contacts → | ||||
Indirect evidence “Information security and compliance can be a challenging process across many areas and for many organisations.” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 24 | 3 contacts → | ||||
Indirect evidence “Husain Bulman & Co Chartered Accountants and Registered Auditors - London, UK” Source: RevenueBase Database · checked Sep 20, 2026Thanks. The Data Team will review it. | |||||
| 25 | 3 contacts → | ||||
Partial evidence “We are an Internal Audit search firm operating within the Financial Services sector.” 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: IT audit 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 IT audit firms.
- Partial evidence
- Its own public description names part of IT audit firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name IT audit 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 101 IT audit firms based in the United Kingdom
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IT audit 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 101 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 IT audit 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 “IT audit 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 IT audit 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 IT audit 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, 253 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.
IT audit firms by metro
- IT audit firms in London36
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 IT audit 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 IT audit firms are there based in the United Kingdom?
RevenueBase identified 101 IT audit 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?
Tiaa LTD, headquartered in Fareham, tops this list with the largest team on record.
Which city has the most IT audit firms?
London leads with 36 headquartered companies, followed by Manchester (3) and Belfast (2).
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 253 verified decision-maker contacts tracked across these 101 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.