In today’s complex regulatory and digital environment, strong internal audit and risk assurance capabilities are essential for effective governance and confident decision-making. This practical guide provides clear context on established UK companies in the field, their core strengths and the organisations they typically serve.
Rather than ranking providers, it helps businesses compare options based on scale, focus and approach.
Acumon
Acumon is a London-based firm delivering risk and technology audit services across the UK, Jersey and the Isle of Man. The firm supports organisations in regulated sectors through independent internal audit engagements as part of a broader risk and technology advisory offering.The service aligns with current market expectations, regulatory developments and board-level priorities around governance and technology risk. Acumon helps senior leaders and audit committees address these areas with independent oversight.Acumon applies a practical risk-based methodology to internal audit work. It identifies control weaknesses, strengthens governance and technology frameworks, tests effectiveness and delivers greater confidence in risk management and reporting integrity. The firm’s proactive team often responds within hours on average, leveraging its in-house software development team for efficient, tech-enabled processes
Key Highlights:
- London-based with Jersey and Isle of Man coverage
- ICAEW registered and FRC authorised
- Dedicated risk and technology assurance practice
- Governance and regulatory oversight expertise
- Specialised IT risk and cybersecurity focus
- Experience with regulated-sector clients
- Proactive, tech-enabled approach with in-house software development team
Services:
- Internal audit services in UK
- Technology risk assessments
- Cybersecurity reviews
- Systems control evaluations
- Technology governance advisory
- Digital resilience assurance
- Control effectiveness testing
Contact Information:
- Website: acumon.com
- Phone: 020 8567 3451
- Email: mail@acumon.com
- Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
Deloitte
Deloitte supplies internal audit support that follows the Institute of Internal Auditors’ professional standards, along with public sector guidelines where relevant. The approach centres on giving organisations assurance around major risks while helping them adapt to changes in their environment. Services include full outsourcing of internal audit functions, co-sourcing arrangements for extra support, and advisory work focused on building or improving internal audit capabilities.
The offering stresses anticipation of emerging issues and use of technology to make processes more efficient. Organisations get help with transforming how internal audit operates, often in response to stakeholder expectations or regulatory shifts.
Key Highlights:
- Alignment with IIA Standards
- Focus on risk anticipation and learning acceleration
- Options for outsourcing and co-sourcing
- Advisory on transformation and adaptation
Services:
- Outsource internal audit
- Co-source internal audit support
- Advisory services for internal audit functions
EY
EY delivers internal audit transformation services through its consulting arm, with attention to building trust and managing business risks effectively. The method combines people, processes, and technology, often using tools like EY Virtual Internal Auditor to shift routine tasks to automation. Diagnostic assessments help evaluate current internal audit setups, while transformation efforts aim to close gaps in maturity and add digital capabilities.
Co-sourcing and managed services come into play for industry-specific or risk-focused needs, alongside analytics-driven controls testing to improve coverage and cut costs. The setup supports organisations dealing with evolving regulations, technology changes, and demands for more proactive insights.
Key Highlights:
- Use of EY Virtual Internal Auditor tool
- Emphasis on holistic transformation
- Support for SOX and similar compliance
- Diagnostic and benchmarking options
Services:
- Internal audit diagnostic services
- IA transformation and capability building
- Co-source and managed services
- Analytics-based controls testing
- Risk domain-focused support
Grant Thornton
Grant Thornton provides risk-based internal audit services designed to offer objective assurance and practical insights. The service draws on professionals with risk expertise and subject matter specialists to address emerging risks and strengthen controls. Arrangements include outsourcing, co-sourcing, or temporary staff support depending on what the organisation requires.
External quality assessments help review internal audit effectiveness against IIA standards, while integrated experts add depth to assurance around new business initiatives. The approach stays collaborative and adapts to the client’s culture and maturity level.
Key Highlights:
- Risk-based methodology
- Access to subject matter experts
- IIA-compliant external quality assessments
- Support for resource gaps at various levels
Services:
- Outsource and co-source internal audit
- Loan staff arrangements
- External quality assessments
- Insight and challenge on emerging risks
Protiviti
Protiviti offers internal audit consulting services in the UK with a focus on risk-based audits, assessments, and advisory work. The services cover technology audits for IT risks and governance, audit transformation to improve efficiency and value, and innovation through tools like data analytics, AI, and automation. Sourcing options range from full outsourcing and co-sourcing to staff augmentation, often drawing on specialist expertise in controls, compliance, fraud risk, SOX compliance, and capital projects.
The approach aligns with Institute of Internal Auditors standards, including the Three Lines Model for independence. It addresses various audit types such as operational, compliance, IT/cybersecurity, ESG, and third-party risks while integrating technology for continuous assurance and better decision-making. UK regulatory aspects like the Corporate Governance Code and sector rules get consideration in the delivery.
Key Highlights:
- London office presence
- Alignment with IIA Standards
- Technology integration including AI and analytics
- Flexible sourcing models
- Coverage of emerging risks like cyber and ESG
Services:
- Technology audit
- Audit transformation
- Audit innovation
- Controls advisory
- Fraud risk management
- SOX compliance
- Internal audit strategic sourcing
Crowe
Crowe handles internal audit by combining insight, assurance, and value with a forward-looking view that goes beyond basic controls testing. The setup serves as strategic advisers to anticipate risks, optimise processes, and support changes in systems, processes, and people. Experience spans various industries and client sizes, with involvement in the Institute of Internal Auditors’ Principal Partner Program.
Services include transformation of internal audit functions to align with strategic priorities, outsourcing or co-sourcing as a full or partial provider, staff augmentation for quick responses to needs like turnover or regulatory issues, SOX readiness and optimisation, quality assessment reviews against IIA standards, AI applications for efficiency, and design plus implementation of internal audit technology platforms through alliances like AuditBoard or ServiceNow.
Key Highlights:
- Forward-looking perspective
- IIA Principal Partner Program involvement
- Experience with SOX and compliance
- AI and analytics opportunities
- Platform alliances
Services:
- Internal audit transformation
- Outsourcing and co-sourcing
- Staff augmentation
- SOX readiness, compliance, remediation, optimisation
- Quality assessment reviews
- AI for internal audit
- Internal audit technology platform design and optimisation
RSM
RSM provides internal audit services that contribute to risk management and business operations for various organisations. Professionals work to understand business strategy, drivers, and operational processes before delivering independent evaluations of the control environment. Where improvements appear necessary, support extends to identifying solutions that help meet objectives.
The offering includes advice on developing workable internal controls, implementing secure control environments, managing core operational risks tied to business reliability, linking strategies and risk measures to goals, assisting change management through training and skill development, and evaluating structures for effective corporate governance. Related risk advisory covers fraud prevention, anti-money laundering, information systems assurance, governance, compliance, and regulatory matters.
Key Highlights:
- Focus on business strategy alignment
- Independent control environment reviews
- Support for improvement solutions
- Advice on operational risks
Services:
- Advising on internal controls development
- Implementing effective control environments
- Managing core operational risks
- Linking strategies to risk performance
- Change management and staff training
- Corporate governance evaluations
Bishop Fleming
Bishop Fleming delivers core internal audit and risk assurance to public and private sector organisations, from one-off compliance checks on key controls to annual plans covering multiple areas. The work involves establishing, developing, and strengthening internal control frameworks to meet requirements in sectors like education, housing, NHS, and government. Reviews stay tailored and focused on what matters most to the client for better resilience and risk awareness.
Services encompass internal audit, risk management, governance, and systems and controls assurance. The method emphasises bespoke reviews that provide clarity on risks and controls without a one-size-fits-all approach.
Key Highlights:
- Coverage across public and private sectors
- Bespoke review approach
- Sector focus including education and government
- Emphasis on control framework strengthening
Services:
- Internal audit
- Risk management
- Governance
- Systems and controls assurance
TIAA
TIAA delivers internal audit as part of its business assurance services, with a risk-based method that identifies strategic, operational, and financial risks. The service provides independent assurance on risk management, governance, and internal controls while considering the broader context of each client’s operations. Many auditors bring prior operational experience from relevant sectors, which helps in offering pragmatic advice and realistic solutions to day-to-day challenges.
Options range from full outsourcing and co-sourcing to ad-hoc assignments, often incorporating data analytics for better planning and results. The approach stays collaborative, agreeing on prioritised corrective actions when control weaknesses come up. Coverage spans clients across England, Wales, Scotland, and Northern Ireland, with access to benchmarking information for added context.
Key Highlights:
- Risk-based audit approach
- Use of data analytics in delivery
- Collaborative corrective action planning
- Sector-tailored assurance
- Coverage across UK nations
Services:
- Governance audits
- Risk management and assurance frameworks
- ICT and cyber security reviews
- Financial and operational performance audits
- Capital projects and investment assessments
- Value for money evaluations
- Project consultancy
- Sustainability reviews
Lighthouse Consultants
Lighthouse Consultants carries out internal audit services that assess and strengthen internal controls, compliance, and operational processes for UK organisations. The work includes control evaluations to spot gaps, compliance reviews against regulations, and operational audits to find inefficiencies. Reports come with clear recommendations aimed at practical improvements.
Co-sourcing supports existing in-house functions with partial outsourcing or capability boosts, while full outsourcing provides independent assessments without an internal team. Consultancy focuses on governance, risk management, and efficiency gains, sometimes delivering third-party assurance like ISAE 3402 reports. The setup draws on combined experience from consultants based in Aberdeen, Dundee, Edinburgh, and Glasgow.
Key Highlights:
- Co-sourced and outsourced options
- Focus on public sector standards
- Third-party assurance reporting
- Enterprise risk management consulting
Services:
- Internal controls and compliance audits
- Enterprise risk management consulting
- Third party assurance and SOC reports
- Operational process reviews
PKF Littlejohn
PKF Littlejohn has been providing outsourced and co-sourced internal audit services for many years to complex and highly regulated listed and private companies, particularly in the financial services sector. They help establish effective internal audit functions, support in-house teams, and deliver independent assurance amid increasing regulatory scrutiny, operational complexity, and evolving risks.
Their approach is flexible and tailored, with a strong focus on preventing control failures, financial losses, and reputational damage.
Key Highlights:
- Offices in London, Leeds, Manchester
- Expertise in highly regulated sectors (financial services)
- Flexible outsourced/co-sourced models
- Ad hoc reviews and training/support options
Services:
- Outsourced internal audit (full setup & Head of IA role)
- Co-sourced internal audit support
- Ad hoc control assurance reviews
- Internal audit training
- Support to Heads of Internal Audit
Price Bailey
Price Bailey provides internal audit services focused on independent assurance over systems, controls, and processes. The firm helps organisations achieve objectives by identifying hidden risks, streamlining operations, and strengthening controls. Services are value-adding, delivering practical recommendations that go beyond compliance to support better decision-making.
Specialised in academy trusts (DfE-compliant reviews) and not-for-profits (charities, councils, smaller authorities), with efficient remote delivery via the Inflo portal.
Key Highlights:
- Remote/flexible approach + Inflo technology
- Positive testimonials from academy trusts and councils
- Specialist in AGAR internal audits for smaller authorities
Services:
- Independent assurance on systems, controls & processes
- Risk identification & practical recommendations
- Bespoke reviews (governance, cyber, GDPR, fraud, grants, etc.)
- AGAR-related audits & Annual Internal Audit Report
- Tailored scoping, fieldwork, reporting & board presentations
Complyport
Complyport conducts risk-based internal audits for financial services firms, drawing on knowledge of regulatory frameworks and practical industry understanding. The process involves desk-based or onsite inspections, custom audit planning from reviews of company information and processes, and compliance health checks that evaluate controls and performance against legislation. Reports detail findings, weaknesses, and recommendations presented to senior management or boards.
Additional work includes anti-money laundering and counter-terrorist financing checks, systems audit trail verification for platform suitability and controls, plus extraordinary investigations or ad-hoc engagements for areas like governance, risk management, or fraud. The setup often follows an FCA-inspired review-and-recommend model, with options to appoint a named individual as internal auditor.
Key Highlights:
- Risk-based inspection approach
- FCA/PRA Skilled Persons Panel inclusion
- Focus on financial services regulations
- Remedial activity support
Services:
- Risk-based internal audits
- Customised audit planning
- Compliance health checks
- AML and CTF checks
- Internal audit reporting
- Systems audit trail verification
- Extraordinary investigations and ad-hoc engagements
Azets
Azets is a UK firm with a broad network of offices across the country that specialises in internal audit and risk assurance services. The firm works with organisations from various sectors to provide independent assurance over governance structures, risk management processes and the design and operating effectiveness of internal controls. Using a combination of local presence and digital delivery options, Azets tailors its approach to the specific needs, scale and regulatory environment of each client.
The internal audit offering is delivered through a partner-led model that emphasises practical and actionable outcomes. Azets focuses on evaluating existing control frameworks, identifying areas of weakness and supporting the development of stronger governance and risk management practices. This helps senior leadership and audit committees gain improved visibility and confidence in how key risks are being managed and controlled across the organisation.
Key Highlights:
- Nationwide UK office network
- Partner-led internal audit delivery
- Tailored sector and regulatory expertise
- Focus on governance and control effectiveness
- Flexible in-person and remote services
- Practical risk management support
Services:
- Internal audit and assurance services
- Governance reviews
- Risk management framework assessments
- Internal control evaluations
- Technology and systems assurance
- Control effectiveness testing
AAB
AAB provides internal auditing and assurance services to help organisations identify and address risks across different sectors. The approach stays objective and clear, with reporting often directed to boards and senior management while considering their risk appetite. Work draws on in-depth knowledge of each client’s operations and objectives for proactive assessments of current and future concerns.
Services cover internal audit projects targeted at high-risk or emerging areas, plus risk management support through workshops, risk registers, and assurance maps to spot gaps or overlaps. The offering suits UK entities, international clients, public sector, social housing, and education organisations dealing with issues like major projects or policy reviews.
Key Highlights:
- Objective and unbiased evaluations
- Proactive risk assessment
- Sector coverage including public and social housing
- Reporting to senior management
Services:
- Internal audit projects
- Risk management services
Xcina Consulting
Xcina Consulting delivers internal audit services with a risk-based focus that provides assurance on governance, risk management, and internal controls. The approach addresses challenges from complex operating environments, regulatory shifts, and technology changes where internal resources often fall short, especially in niche or emerging risk areas. Outsourced services offer independent oversight of governance arrangements, risk activities, and controls while highlighting improvement opportunities to support confident management execution.
Options include full outsourcing as a turn-key function handling planning through to remediation follow-up, co-sourcing to extend existing teams on capacity, expertise, or independence needs, transformation to align with professional standards and stakeholder expectations, quality assurance reviews checking compliance with CIIA requirements, and tailored training in risk-based methodologies plus specialist topics. The setup emphasises efficiency, quality concentration on high-risk areas, and knowledge transfer for lasting in-house benefits.
Key Highlights:
- Risk-based assurance delivery
- Alignment with CIIA standards
- Flexible outsourcing models
- Focus on emerging and niche risks
- Knowledge transfer emphasis
Services:
- Internal audit transformation
- Full outsourcing of internal audit
- Co-sourcing support
- Internal audit quality assurance reviews
- Training in audit methodologies and specialist areas
Conclusion
The choice of internal audit and risk assurance partner depends on your organisation’s size, sector, regulatory needs and the maturity of its governance and control environment. Some companies suit integrated technology-driven models, while others excel in targeted high-level advisory support.
This guide offers neutral context to compare the main players and identify the most suitable strategic partner. Understanding each company’s focus helps organisations select the right match for their specific requirements.
The right internal audit partner delivers independent oversight and practical steps to strengthen controls and reduce risks.
