Blog · 2026-03-09 · manager

Leading Internal Audit Services Companies in the UK

Internal audit is not just a regulatory checkbox. For many UK businesses, especially those operating in regulated sectors, it has become a practical tool for understanding where risks sit and whether internal controls are actually working as intended. The companies that provide internal audit services across the UK tend to operate quietly in the background, […]

What stands out in the UK market is the balance between technical depth and commercial awareness. Internal audit firms are not only assessing compliance with governance frameworks or financial controls. They are often working alongside boards, audit committees, and senior management to provide assurance that operational, financial, and technology risks are being managed in a structured and defensible way. In many cases, their role shifts between independent reviewer and trusted advisor, depending on what the organisation needs at that stage.

1. Acumon

At Acumon, we approach internal audit as part of a wider risk and assurance conversation. Based in London and working with organisations across the UK, we support CFOs and Finance Directors who want clarity around governance, internal controls, and technology risk. Internal audit often sits within our Risk and Tech Assurance work, where we look at how processes actually function day to day – not just how they appear on paper. Some clients bring us in after a period of growth, when systems have not quite kept pace. Others simply want independent assurance before their year ends.

Our internal audit perspective is grounded in statutory and regulatory experience. That matters when reviewing areas such as client money handling, FCA compliance, or sector specific reporting. In practice, our work can involve sitting with finance teams, walking through control processes, reviewing IT risk frameworks, or testing governance procedures in person at client sites. We keep the reporting structured and clear. The aim is not to overcomplicate findings, but to highlight what needs attention and where controls are working as intended.

Key Highlights:

Experience across regulated sectors
Internal audit delivered as part of Risk and Tech Assurance
On-site and remote engagements across the UK
Experience supporting FCA-regulated entities and charities
Registered audit firm with ICAEW and FRC authorisation

Services:

Internal audit programmes for medium and large organisations
Governance and compliance reviews
IT risk and cybersecurity assurance
Risk management framework assessments
CASS and FCA-related assurance reviews

Contact Information:

Website: acumon.com
E-mail: mail@acumon.com
Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
Phone: 44 (0) 20 8567 3451

2. Protiviti

Protiviti provides internal audit services as part of a broader risk and consulting offering. Their approach combines traditional internal audit work with technology, data analysis, and transformation support. They work with organisations that want their audit function to evolve – sometimes fully outsourced, sometimes supported through co-sourcing or staff augmentation. In practice, that can mean stepping in as an extended internal audit team, or working alongside an existing function that needs specific technical expertise.

Technology audit and SOX advisory form a visible part of Protiviti’s internal audit work. They also support audit committees and Chief Audit Executives with programme reviews and transformation projects. Rather than limiting internal audit to control testing, they often position it as a forward-looking function, using analytics, automation and risk based planning. For larger or more complex organisations, that structure can make sense – especially where regulatory pressure or digital change has increased the volume of risk areas to cover.

Key Highlights:

Internal audit outsourcing, co-sourcing and staff augmentation models
Focus on technology-enabled audit and data-driven methods
Experience supporting SOX and complex control environments
Advisory support for audit committees and senior leadership

Services:

Risk-based internal audit programmes
Technology and IT risk audit
SOX compliance and advisory
Audit transformation and effectiveness reviews

Contact Information:

Website: www.protiviti.com
Facebook: www.facebook.com/protiviti
Twitter: x.com/protiviti
LinkedIn: www.linkedin.com/company/protiviti
Instagram: www.instagram.com/protiviti
Address: The Shard, 32 London Bridge Street, London, SE1 9SG, United Kingdom
Phone: +44 20 7930 8808

3. Grant Thornton

Grant Thornton offers internal audit services using its business risk advisory groups. They partner with groups needing independent assurance and advice on improving processes and controls. Their internal audit help can be co-sourced, fully outsourced, or given through short-term staffing. Often, they assist when an internal team is busy or when expertise is needed.

A key part of how Grant Thornton works is adding experts to audit projects. This could mean getting experts in areas like ESG, cyber, financial services rules, or public sector management, depending on what’s needed. They also do external quality checks to assess how well internal audit teams are working. Their internal audit work focuses on solid assurance mixed with helpful feedback, not just going through the motions.

Key Highlights:

Co-source, outsource and interim internal audit support
External quality assessments aligned with IIA standards
Sector-specific internal audit capability
Integration of specialist risk expertise

Services:

Risk-based internal audit
Internal audit outsourcing and co-sourcing
External Quality Assessments
Governance and control reviews
Emerging risk assurance

Contact Information:

Website: www.grantthornton.co.uk
LinkedIn: www.linkedin.com/company/grant-thornton-uk
Instagram: www.instagram.com/gt_trainees
Address: 8 Finsbury Circus London EC2M 7EA
Phone: +44 (0)20 7383 5100

4. Complyport

Complyport tends to work with regulated financial services firms, and that focus shapes the way they approach internal audit. A lot of what they do is built around FCA expectations and the practical realities of operating under tight regulatory rules. They are not trying to cover every sector under the sun. Instead, they stay in compliance-heavy environments where the detail actually matters. Their internal audits usually follow a review-and-recommend format, mixing desk-based work with time spent on site, looking at how things are really being handled rather than how they are described in policy documents.

Alongside core internal audit work, Complyport also carries out compliance health checks, AML reviews and more targeted investigations when something specific needs attention. For smaller regulated firms, they can appoint a named individual to act as Internal Auditor, which is often a more workable option than building a full in-house team from scratch. Their reports are typically prepared for senior management and boards, especially where there are gaps to address or controls that need tightening. It is fairly structured work, but it is grounded in day-to-day regulatory practice rather than theory.

Key Highlights:

Review-and-recommend internal audit approach
Combination of desk-based and on-site inspections
Option to appoint a named Internal Auditor

Services:

Compliance health checks
AML and CTF reviews
Systems and audit trail verification
Regulatory gap analysis

Contact Information:

Website: complyport.com
E-mail: info@complyport.co.uk
Twitter: x.com/complyport
LinkedIn: www.linkedin.com/company/complyport-ltd
Address: 34 Lime Street London EC3M 7AT United Kingdom
Phone: +44 (0)20 7399 4980

5. Albion

Albion is an internal audit and risk company in the UK that works with groups of all sizes. They pay attention to how companies are run and managed, risks, and keeping things under control. They want their services to be easy to use instead of being too corporate. Albion helps clients with all of their internal audit needs, but they also have smaller, simpler choices. For example, their Ask Albion service lets groups ask specific questions about audits or risks without having to agree to a full project. This setup can be good for smaller teams that just need specific advice instead of a long set of reviews. They work remotely and in person, based on what the client wants.

The way they do things follows well-known guides like IIA and COSO, and they bring in pros in areas like IT audit and cyber risk. Albion also says they are making computer programs based on AI to make things work better, which means they are trying to bring audit help up to date. But, they still focus on what works – like internal controls, risk checkups, and reviews of how groups are run – instead of wide-ranging business advice.

Key Highlights:

Alignment with IIA and COSO frameworks
On-site and remote internal audit delivery
Access to IT and cyber risk specialists

Services:

Full internal audit outsourcing and co-sourcing
Risk and control reviews
Internal audit health checks
IT audit and cyber risk assessments
Governance framework reviews

Contact Information:

Website: albionaudit.com
E-mail: info@albionaudit.com
Facebook: www.facebook.com/people/Albion-Audit-and-Risk-Limited/61578057165299
Twitter: x.com/AlbionAuditUK
LinkedIn: www.linkedin.com/company/albion-audit-and-risk-limited
Instagram: www.instagram.com/albionaudit
Address: 279 Chanterlands Avenue, Hull, HU5 4DS, United Kingdom
Phone: +44 7594 738595

6. SWAP

SWAP operates as a not-for-profit internal audit partnership, primarily serving public sector organisations. Their roots are in local government, and that background shapes how they approach audit and assurance work. They focus on improving governance, risk management and operational efficiency within councils, housing bodies, police and fire authorities, and other public entities. Internal audit is delivered with an understanding of how public sector finance and accountability frameworks actually work in practice. Most engagements involve direct, on-site collaboration with client teams.

In addition to core internal audit, SWAP provides services in counter fraud, technology auditing and data analytics. They describe themselves as business improvement specialists, which comes through in the way they combine assurance with practical recommendations. Because they operate as a partnership model, they often work closely with other public sector networks and professional bodies. Their approach is structured but grounded in day-to-day operational realities rather than theory.

Key Highlights:

Not-for-profit internal audit partnership
Focus on local government and wider public sector
Conformance with IIA professional standards
Experience in fraud investigation and technology audit

Services:

Counter fraud services
Technology and cyber audit
Data analytics
Business improvement reviews
Asset management and financial system audits

Contact Information:

Website: www.swapaudit.co.uk
E-mail: enquiries@swapaudit.co.uk
LinkedIn: www.linkedin.com/company/swap-internal-audit-services
Address: Ground Floor, Blackbrook Gate 1, Blackbrook, Business Park, Taunton, Somerset, TA1 2PX
Phone: 020 8142 5030

7. Veritau

Veritau works mostly with public sector organisations. Their auditors spend time looking at risks, controls and governance arrangements, but they also try to see how those systems actually function in practice. A lot of the work happens on site, especially when it helps to sit with teams and understand how services are delivered rather than just reading policies. They are also conscious that in areas like social care or education, staff are stretched, so they plan audits in a way that does not create unnecessary disruption.

Veritau adjusts each audit plan depending on the organisation and its priorities. Reviews might focus on financial systems, operational processes, IT risk or value for money. They also look ahead, not just backwards. In some cases, they have carried out independent reviews to help councils prepare for inspections, acting a bit like a critical friend before the official visit. Their teams are professionally qualified and many have worked in local government finance or risk roles before, which gives their reports a practical tone rather than a theoretical one.

Key Highlights:

Independent internal audit delivered on site and remotely
Experience across councils, schools and academies
Professionally qualified audit teams
Support with inspection preparation and risk management

Services:

Risk-based internal audit programmes
Financial system and governance reviews
IT audit and data analytics
Value for money assessments

Contact Information:

Website: veritau.co.uk
E-mail: enquiries@veritau.co.uk
Facebook: www.facebook.com/www.veritau.co.uk
LinkedIn: www.linkedin.com/company/veritau
Instagram: www.instagram.com/veritaultd
Address: West Offices Station Rise York, YO1 6GA
Phone: 01904 552943

8. Henderson Loggie

Henderson Loggie delivers internal audit services across the UK. Their internal audit team works with organisations in the public, private and third sectors, offering co-sourced, outsourced and consultancy support. They tend to focus on governance, risk management and operational improvement rather than treating audit as a narrow compliance task. In practice, that can mean supporting an Audit Committee with its annual assurance framework or reviewing how a risk register is actually being used, not just whether it exists.

Alongside traditional internal audit reviews, Henderson Loggie also provides advisory support in areas such as enterprise risk management, digital governance and fraud prevention. Their work often blends assurance with practical input. For example, they might review internal controls against sector standards and then sit down with management to talk through where processes can realistically be tightened. They also undertake third party assurance reporting and business process optimisation work, which suggests their remit extends beyond core audit cycles into broader improvement projects.

Key Highlights:

Co-sourced, outsourced and consultancy internal audit models
Experience supporting public sector audit and assurance frameworks
On-site and remote internal audit delivery
Integration of digital governance and fraud expertise

Services:

Risk-based internal audit programmes
Internal controls and compliance reviews
Enterprise risk management consulting
Digital and information governance assurance
Fraud prevention and forensic investigations

Contact Information:

Website: hlca.co.uk
E-mail: info@hlca.co.uk
Facebook: www.facebook.com/HendersonLoggie
LinkedIn: www.linkedin.com/company/hendersonloggie
Instagram: www.instagram.com/hendersonloggie
Address: The Vision Building 20 Greenmarket Dundee DD1 4QB
Phone: 01382 200055

9. Insights

Insights offers internal audit services in the UK as part of their broader advisory services. Their internal audit support covers outsourcing, co-sourcing, and consulting, focusing on planning, risk assessment, and well-organized audits. They use a step-by-step method, starting with setting the scope and goals, then looking at risks, planning the audit, and doing tests. Usually, this means talking with managers, creating an audit plan, and doing thorough reviews. They can do these audits at your office or remotely, depending on what works best for you.

Their internal audits aim to improve risk management, governance, and internal controls. Insights stresses using both analytical and substantive testing, as well as keeping records and reporting to top management. The process seems systematic, with formal reports and follow-up talks to discuss any problems found. While their style is structured, the main goal is simple: to help organizations see which controls are working well and where changes might be needed.

Key Highlights:

Internal audit outsourcing and co-sourcing options
Structured risk assessment and audit planning process
Combination of analytical testing and control reviews
Reporting directly to executive management

Services:

Internal audit planning and execution
Risk assessment and audit programme development
Control testing and gap identification
Internal audit reporting
Compliance and governance reviews

Contact Information:

Website: uk.insightss.co
E-mail: uk@insightss.co
Facebook: www.facebook.com/people/Insights-UK/100091940786798
Twitter: x.com/InsightssUK
LinkedIn: www.linkedin.com/company/insightsuk
Instagram: www.instagram.com/insightssuk
Address: 37th Floor, 1 Canada Square, London E14 5AA
Phone: +44 7502 237970

10. JR Consultants

JR Consultants concentrates on ISO internal audits. Their work is less about broad corporate governance and more about how management systems actually function. They step in as an independent party, reviewing whether a business really meets the standard it is certified to – or wants to be certified to – and where things could realistically be tightened up. A lot of their time is spent on site, talking to staff, going through procedures, and seeing how processes are carried out in real life rather than just reading what is written in a manual.

The way they run an audit is fairly straightforward. First, they get to grips with how the organisation operates. Then they plan the review, carry out interviews, check documents and observe day-to-day activities. After that, they produce a report that sets out what is working and what may need attention. JR Consultants can also stay involved after the audit, offering ongoing support or acting as a management representative during certification visits. Their view seems to be that an internal audit should not feel like a box-ticking exercise. It is more about spotting small weaknesses before they become bigger issues and making management systems run more smoothly in practice.

Key Highlights:

Focus on ISO internal audit services
Independent internal audit delivery on site and remotely
Structured audit methodology aligned to ISO standards
Support ahead of certification and surveillance audits

Services:

Internal audits
Management system reviews
Audit preparation and management representative support

Contact Information:

Website: www.jrconsultants.co.uk
E-mail: info@jrconsultants.co.uk
Facebook: www.facebook.com/jrconsultantsfamily
Address: Unit 6d, Dollymans Farm, Doublegate Lane, Rawreth, Wickford, Essex SS11 8UD
Phone: 01268 758000

11. Larking Gowen

Larking Gowen provides internal audit services mainly to clients in the local government, education and charity sectors. Their education work is focused on multi academy trusts, where they often carry out deep-dive reviews into specific risk areas identified by the audit committee. Instead of covering everything at once, they tend to look closely at two or three key topics during the year – areas like payroll, governance, SEND funding or compliance with the Academy Trust Handbook. It is a fairly targeted approach, shaped by what the trust sees as its main risks at the time. Most of their fieldwork is carried out on location so they can see how controls are actually operating.

In local government, Larking Gowen works with town and parish councils. Their reviews are structured around the Annual Governance and Accountability Return requirements, and they usually visit twice a year – once during the financial year and once shortly after year end. That timing allows them to look at how controls have worked over a full twelve-month period. Reports are written in a format that is easy for councillors and trustees to follow, with RAG-rated summaries and clear recommendations rather than dense technical language.

Key Highlights:

Deep-dive internal audit reviews for multi academy trusts
Twice-yearly internal audit visits for councils
RAG-rated reporting format for clarity
On-site internal audit delivery

Services:

Risk-based internal audit for multi academy trusts
Financial and non-financial control reviews
Academy Trust Handbook compliance reviews
Internal Scrutiny Annual Reports
Internal audit for town and parish councils

Contact Information:

Website: www.larking-gowen.co.uk
Facebook: www.facebook.com/LarkingGowen
Twitter: x.com/LarkingGowen
LinkedIn: www.linkedin.com/company/larking-gowen
Instagram: www.instagram.com/larkinggowen
Address: 1 The Atrium Phoenix Square, Wyncolls Road, Colchester CO4 9AS
Phone: 01206 843999

12. Moore UK

Moore UK provides internal audit, governance, and risk services to businesses, nonprofits, schools, housing groups, and public sector organizations. Their internal audit services are part of a larger package of governance and assurance solutions. They offer both outsourced and co-sourced internal audit programs, with planning that usually follows standards like the UK Corporate Governance Code and IIA guidance. This means they create audit plans based on an organization’s specific risks, instead of using a standard plan for everyone.

In addition to internal audit testing, Moore UK gives advice on corporate governance and enterprise risk management. They examine board and committee structures, reporting procedures, and policy frameworks. They also help organizations document their risk tolerance and improve their oversight procedures. Their reports are clear and straightforward, designed for audit committees and boards that need useful information instead of technical jargon.

Key Highlights:

Internal audit integrated with governance and risk advisory
Outsourced and co-sourced delivery options
Alignment with UK governance and IIA standards
Sector coverage including corporate and not-for-profit

Services:

Risk-based internal audit programmes
Operational, financial and compliance reviews
IT and cyber assurance
Corporate governance framework reviews
Enterprise risk management support
Risk appetite development and workshops

Contact Information:

Website: www.moore.co.uk
E-mail: peter.morley@moore-insight.com
Twitter: x.com/MooreUKNetwork
LinkedIn: www.linkedin.com/company/moore-uk
Address: St James House Vicar Lane Sheffield South Yorkshire S1 2EX United Kingdom
Phone: +44 (0)20 7952 4691

13. JCBFL

JCBFL offers outsourced and co-sourced internal audit support. Their approach is built around the three lines of defence model, with internal audit sitting as the third line and reporting to the Audit Committee. They make it clear they are not interested in box-ticking exercises. Instead, their focus is on whether governance, risk management and internal controls are actually doing what they are supposed to do, especially in regulated environments. A lot of their assignments are carried out on site, particularly when investigations are sensitive or when control testing means getting direct access to systems and people.

Alongside routine internal audit work, JCBFL also handles more specific projects such as forensic investigations and five-year external quality assessments of internal audit functions. They sometimes step in where an organisation has never had a formal internal audit setup and needs help building one from scratch. Their fee structure is fairly flexible, often based on hourly or day rates, which can work well for businesses that only need targeted input rather than a full, long-term arrangement. Overall, the impression is practical and no-nonsense – focused on assurance in regulated sectors without the overheads you would expect from a much larger firm.

Key Highlights:

Third line of defence assurance model
Co-sourced and outsourced internal audit support
Experience with internal audit quality assessments

Services:

Internal audit plan delivery
Governance, risk and control assurance
Forensic investigations
External Quality Assessments
Internal audit function development

Contact Information:

Website: www.jcbfl.co.uk
E-mail: jane.cassidy@jcbfl.co.uk
LinkedIn: www.linkedin.com/in/jane-cassidy-4482a3172
Phone: 01920 872324

14. Wbg

Wbg offers internal audits for groups in different fields. Their team helps clients look at their internal rules and how they’re run, mainly focusing on handling risks. Instead of just seeing checks as a must-do, they treat it as a way to see how rules work in practice. This could mean talking with money teams at a housing group to go over rent rules, or checking how decisions are recorded and watched in an education group. Wbg’s checking service also ties into computer checks, probes, and fraud accounting. This wider range of skills lets them look past normal tests when needed. If a weak rule points to a bigger issue, they can look into it more.

Their service seems simple: they check risk, how groups are run, and internal rule systems, and then clearly report to leaders and boards. Their team has trained checkers, and their focus suggests they know the rules and money situations that education and non-profits deal with.

Key Highlights:

Internal audit across education, social housing, charities and private sector
Integration with IT audit and forensic services
Focus on governance, risk and internal controls

Services:

Governance and control reviews
IT audit
Investigations
Forensic accounting support

Contact Information:

Website: wbg.co.uk
E-mail: info@wbg.co.uk
Twitter: x.com/WbgAccountancy
LinkedIn: www.linkedin.com/company/wylie-&-bisset-llp
Address: 168 Bath Street Glasgow, G2 4TP
Phone: 0141 566 7000

Conclusion

Internal audit services in the UK cover a fairly wide spectrum. Some firms focus heavily on regulated sectors like financial services or insurance. Others concentrate on public bodies, schools and housing associations. Then there are those that sit somewhere in between, offering governance and risk support across different industries. What becomes clear is that internal audit is no longer just about reviewing paperwork once a year. It is increasingly tied to how organisations manage risk in real time, especially when funding pressures, regulation and technology risks keep shifting.

Choosing the right internal audit partner usually comes down to fit. Sector experience matters. So does the way the firm works – whether they integrate smoothly with an existing team, whether they can operate on site when needed, and whether their reports are practical enough to act on. A good internal audit provider should leave an organisation with clearer insight, not just a list of findings. In the end, internal audit works best when it feels like a useful check-in on how things are really running, rather than an exercise people are just trying to get through.