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Choosing Tax Investigation Support in the UK: Companies Overview

Dealing with a tax investigation is rarely straightforward. Whether it’s a routine enquiry or something more complex, the process can quickly become time-consuming, technical, and, at times, stressful.

Across the UK, there’s a wide mix of firms that support businesses and individuals through these situations. Some are large advisory networks with dedicated dispute teams, while others are smaller specialist practices focused specifically on tax investigations and HMRC enquiries. The way they approach cases, and the type of clients they typically work with, can vary quite a bit.

This guide brings together a selection of tax investigation services companies operating in the UK. It’s not intended as a ranking or endorsement. Instead, the aim is to give a clearer sense of the landscape: who these firms are, the kind of support they provide, and how their services are typically positioned.

Acumon

Acumon is a UK firm of chartered accountants and tax advisors providing representation in HMRC tax investigations, enquiries and disputes.

The firm supports individuals, businesses and corporate groups in managing HMRC enquiries, from initial notification through to resolution, including settlement negotiations and, where required, formal appeals.

Work includes assessment of HMRC enquiries, development of structured response strategies, preparation of supporting documentation and direct engagement with HMRC throughout the investigation process.

Many members of the tax team have previously worked within HMRC, providing practical insight into investigation procedures, risk assessment, negotiation approach and penalty frameworks.

The firm also supports voluntary disclosures and complex investigation scenarios, including Code of Practice 9 (COP9) and Contractual Disclosure Facility (CDF) cases, where careful handling and structured negotiation are required.

Tax investigation services are delivered as part of a broader tax offering, particularly where enquiries involve multiple tax regimes such as corporation tax, VAT and employment taxes.

Tax Investigation Capabilities

Acumon provides tax investigation services across a range of HMRC enquiry types.

These include:

  • full enquiries covering multiple tax years
  • aspect enquiries focused on specific issues
  • random enquiries and compliance checks
  • Code of Practice 9 (COP9) investigations
  • Contractual Disclosure Facility (CDF) cases
  • VAT investigations
  • PAYE and employment tax investigations
  • corporation tax enquiries

Engagements are structured around the nature and scope of the HMRC enquiry.

Regulatory Licences and Registrations

Acumon operates within UK tax and regulatory frameworks and holds a number of audit registrations that support its work across multiple jurisdictions.

These include:

  • UK statutory audit registration
  • Public Interest Entity (PIE) audit licence
  • Jersey audit licence
  • Isle of Man audit licence
  • Cayman Islands audit licence
  • British Virgin Islands audit licence

These registrations enable the firm to support organisations operating across both UK and international environments, in line with regulatory and professional requirements.

Core Services

Alongside tax investigation and dispute resolution work, Acumon delivers a range of services that support financial oversight, governance and regulatory compliance.

These include:

  • statutory external audit
  • group and subsidiary audits
  • Public Interest Entity (PIE) audits
  • charity and not-for-profit audit
  • audit of international group structures
  • internal audit and governance reviews
  • risk management and compliance support

Engagements are typically supported by discussions with management and stakeholders around reporting approaches, governance arrangements and control environments.

As organisations develop, they often become subject to more complex reporting and compliance expectations linked to their size, structure or regulatory position.

Acumon works with businesses that are:

  • establishing structured reporting and governance frameworks
  • preparing for investment or funding activity
  • entering or expanding into international markets
  • operating across group or multi-entity structures

Early involvement helps ensure that systems, documentation and internal processes are aligned with regulatory expectations and business requirements.

Contact Information:

Saffery

Saffery handle tax investigations across a mix of individual and corporate clients, often where affairs are more complex or involve international elements. Their work frequently includes dealing with detailed HMRC enquiries where technical interpretation plays a central role, particularly around areas like residence, overseas income or relief claims.

In some cases, the focus is on clarifying specific points in a return, while in others it involves managing full investigations under formal HMRC procedures. When past errors come to light, they guide clients through disclosure options and help structure communication with HMRC in a way that keeps the process clear and controlled.

Key Highlights:

  • Experience with complex and international tax matters
  • Work across multiple tax types including income tax and VAT
  • Involvement in formal HMRC investigations such as COP8 and COP9
  • Support with voluntary disclosures
  • Familiarity with employer compliance enquiries

Services:

  • HMRC tax enquiries handling
  • Code of Practice 8 and 9 investigations
  • Voluntary disclosures to HMRC
  • Employer compliance reviews
  • Tax dispute support
  • Tax enquiry fee protection

Contact Information:

  • Website: www.saffery.com
  • Email: info@saffery.com
  • LinkedIn: www.linkedin.com/company/saffery
  • Instagram: www.instagram.com/saffery_uk
  • Address: Midland House, 2 Poole Road, Bournemouth, Dorset BH2 5QY, UK
  • Phone: +44 (0)1202 204744

AAB

AAB provide tax investigation and dispute resolution support for individuals, businesses and organisations across different sectors. Their work covers a broad range of HMRC enquiries, from routine compliance checks to more complex investigations, including those involving offshore matters or suspected irregularities.

They guide clients through each stage of an enquiry, handling communication with HMRC and working to bring cases to a conclusion within a reasonable timeframe. Their team includes professionals with experience both advising clients and working within HMRC, which influences how they approach negotiations and risk assessment.

Key Highlights:

  • Support across a wide range of HMRC investigations
  • Experience with both domestic and offshore tax matters
  • Involvement in complex cases including COP9 enquiries
  • Background of team members includes HMRC experience
  • Focus on managing penalties and resolving disputes

Services:

  • HMRC tax investigations
  • Tax dispute resolution
  • Voluntary disclosures
  • VAT and customs enquiries
  • Employer compliance reviews
  • Offshore disclosures
  • Professional health check reviews

Contact Information:

  • Website: aab.uk
  • Facebook: www.facebook.com/AABLLP
  • Twitter: x.com/AABGroup_
  • LinkedIn: www.linkedin.com/company/aab-accountants
  • Instagram: www.instagram.com/_aabgroup
  • Address: Gresham House, 5-7 St Paul’s St, Leeds, LS1 2JG
  • Phone: +44 (0)113 297 6789

Alexander & Co

Alexander & Co support clients through different types of tax investigations, from routine checks to more serious enquiries involving detailed financial reviews. Their experience includes dealing with enquiries initiated by various HMRC departments, including specialist investigation units.

Part of their role is helping clients make sense of why an enquiry has been opened and what to expect next. They stay involved through negotiations and discussions with HMRC, particularly where tax liabilities and penalties are being reviewed or challenged.

Key Highlights:

  • Experience across a range of HMRC investigations
  • Work with both individuals and businesses
  • Involvement in complex and specialist enquiries
  • Support during negotiations with HMRC
  • Understanding of investigation triggers and timelines

Services:

  • HMRC tax enquiries support
  • Personal and corporate tax investigations
  • Compliance checks
  • Code of Practice 9 advisory
  • HMRC negotiations
  • Tax dispute assistance

Contact Information:

  • Website: alexander.co.uk
  • Email: info@alexander.co.uk
  • Twitter: x.com/alexandercoMCR
  • LinkedIn: www.linkedin.com/company/alexander-&-co-chartered-accountants
  • Address: Centurion House, 129 Deansgate, Manchester, Greater Manchester M3 3WR
  • Phone: 0161 832 4841

Fusion Accountants

Fusion Accountants focus on supporting smaller businesses and individuals dealing with HMRC enquiries. Their involvement usually centres on taking over communication with HMRC and managing the practical side of the investigation so clients can stay focused on running their business.

A structured fee protection element sits alongside their investigation support, covering the cost of professional fees linked to enquiries. Day-to-day work often includes preparing responses, attending meetings with HMRC and ensuring that requests for information are handled properly.

Key Highlights:

  • Focus on SMEs and individual taxpayers
  • Full representation in HMRC enquiries
  • Handling of HMRC communication and meetings
  • Fee protection available for enquiry costs
  • Experience across different enquiry types

Services:

  • HMRC enquiry representation
  • Self-assessment investigations
  • Corporation tax enquiries
  • VAT disputes
  • IR35 enquiries
  • Tax investigation fee protection

Contact Information:

  • Website: www.fusionaccountants.co.uk
  • Email: info@fusionaccountants.co.uk
  • Facebook: www.facebook.com/fusioncharteredaccountants
  • Twitter: x.com/fusionaccountan
  • LinkedIn: www.linkedin.com/company/fusion-accountants-ltd
  • Address: Ground Floor 90 Long Acre Covent Garden London WC2E 9RZ
  • Phone: 020 8577 0200

Gilbert Tax

Gilbert Tax specialise in tax investigations and tend to be involved where cases are more serious or have been ongoing for some time. Their work often includes stepping into situations where disclosure is required or where HMRC has raised concerns around potential irregularities.

They manage the process directly with HMRC and, where necessary, coordinate with legal advisers if a case progresses further. Some matters move towards tribunal when agreement cannot be reached, and their role then extends into preparing and presenting the case.

Key Highlights:

  • Focus on tax investigations and disputes
  • Experience with complex HMRC enquiries
  • Involvement in disclosure and tribunal cases
  • Work with individuals and accountancy firms
  • Direct handling of HMRC communication

Services:

  • Code of Practice 9 investigations
  • Disclosure facilities
  • Tax tribunal representation
  • VAT and income tax investigations
  • Let property campaign support
  • HMRC enquiry management

Contact Information:

  • Website: www.gilberttax.co.uk
  • Email: scott.gilbert@gilberttax.co.uk
  • Address: 5 Flemming Court, Summit Park, Glasshoughton, WF10 5HW
  • Phone: 0800 011 9625

Armstrong Watson

Armstrong Watson provide a tax investigation service that is closely linked to fee protection arrangements. The structure is designed to cover the cost of dealing with HMRC enquiries, with support provided throughout the investigation once a claim is in place.

Their coverage includes a range of common enquiry types and disputes, including VAT and employer compliance matters. The service also extends to earlier stages such as information requests or compliance checks, where preparation can influence how an enquiry develops.

Key Highlights:

  • Tax investigation service combined with fee protection
  • Coverage across multiple HMRC enquiry types
  • Support during both enquiries and pre-dispute stages
  • Insurance-backed structure for cost recovery
  • Access to additional legal advice support

Services:

  • HMRC enquiry representation
  • VAT and compliance disputes
  • Employer compliance investigations
  • IR35 and employment status disputes
  • Business inspection support
  • Pre-dispute enquiries

Contact Information:

  • Website: www.armstrongwatson.co.uk
  • Facebook: www.facebook.com/armstrongwatson
  • Twitter: x.com/armstrongwatson
  • LinkedIn: www.linkedin.com/company/armstrong-watson
  • Instagram: www.instagram.com/armstrongwatsonllp
  • Address: James Watson House, Montgomery Way, Rosehill, Carlisle, CA1 2UU
  • Phone: 0808 144 5575

Menzies LLP

Menzies LLP support individuals and businesses facing HMRC enquiries, taking on communication with HMRC and guiding clients through each stage of the process. Their involvement can range from relatively focused checks to broader investigations affecting multiple areas of tax.

They offer a subscription-based service that covers professional fees linked to enquiries, which changes how clients approach seeking advice when an issue arises. The scope of their work includes both standard compliance matters and more detailed investigations.

Key Highlights:

  • Support for individuals and businesses
  • Direct liaison with HMRC
  • Subscription-based fee protection model
  • Coverage across different enquiry types
  • Access to internal technical specialists

Services:

  • HMRC tax enquiries
  • Full and aspect investigations
  • VAT and PAYE disputes
  • IR35 enquiries
  • Business inspections
  • Code of Practice 8 investigations

Contact Information:

  • Website: www.menzies.co.uk
  • LinkedIn: www.linkedin.com/company/menzies-llp
  • Instagram: www.instagram.com/menzies_llp
  • Address: 4th Floor, 95 Gresham St, London EC2V 7AB
  • Phone: +44 (0)20 7387 5868

WLH Tax

WLH Tax focus entirely on tax investigations, which shapes how they handle HMRC enquiries across individuals, companies and offshore structures. Their work centres on dealing with complex cases, including those involving suspected fraud, disclosure requirements or cross-border issues. The scope of their involvement often depends on how serious the enquiry is, from standard compliance checks through to criminal investigations.

A noticeable part of their role is stepping in where specialist input is needed, including working alongside accountants or legal advisers who may not deal with investigations on a regular basis. They are involved in managing communication with HMRC, preparing disclosures and supporting cases that move towards tribunal or litigation.

Key Highlights:

  • Focus exclusively on tax investigations
  • Experience with serious and complex HMRC enquiries
  • Involvement in offshore and cross-border matters
  • Work alongside accountants and legal advisers
  • Support through to tribunal and litigation stages

Services:

  • HMRC tax investigations
  • Code of Practice 8 and 9 enquiries
  • Voluntary disclosures and WDF
  • VAT and compliance checks
  • Criminal tax investigations
  • Tax tribunal and litigation support

Contact Information:

  • Website: www.wlhtax.co.uk
  • Email: info@wlhtax.com
  • Address: 5th Floor, International House, 2 – 4 Maddox Street, London, W1S 1QP
  • Phone: 0207 315 4405

Hazlewoods

Hazlewoods provide a tax investigation service that sits alongside their wider accountancy and tax work. The service is structured around supporting clients who are selected for HMRC enquiries, with the same advisers continuing to handle the matter since they already understand the client’s affairs.

The setup includes an insurance-backed element that covers professional fees linked to investigations. Once an enquiry begins, they take over communication with HMRC, attend meetings and manage the process through to resolution, keeping the client informed along the way.

Key Highlights:

  • Tax investigation service linked to existing client relationships
  • Representation by advisers familiar with client affairs
  • Insurance-backed fee protection
  • Handling of HMRC communication and meetings
  • Support throughout the enquiry process

Services:

  • HMRC enquiry representation
  • Full and aspect investigations
  • Handling HMRC correspondence
  • Attendance at HMRC meetings
  • Negotiation with HMRC
  • Tax investigation fee protection

Contact Information:

  • Website: www.hazlewoods.co.uk
  • Email: enquiries@hazlewoods.co.uk
  • Facebook: www.facebook.com/Hazlewoods-104698964298722
  • Twitter: x.com/Hazlewoods
  • LinkedIn: www.linkedin.com/company/hazlewoods
  • Instagram: www.instagram.com/hazlewoods_accountants
  • Address: Staverton Court, Staverton, Cheltenham, GL51 0UX
  • Phone: 01242 680000

RPG Crouch Chapman

RPG Crouch Chapman offer a tax investigation service designed around fee protection and ongoing support during HMRC enquiries. Their service is subscription-based and backed by insurance, covering professional costs when an investigation is opened.

Alongside the investigation support, they provide access to additional resources such as business guidance tools, which sit alongside the core service. Their role during an enquiry includes advising on next steps and helping clients manage the process from start to finish.

Key Highlights:

  • Subscription-based tax investigation service
  • Insurance-backed protection for professional fees
  • Support throughout HMRC enquiries
  • Access to additional business resources
  • Coverage for individuals and businesses

Services:

  • HMRC tax enquiry support
  • Representation during investigations
  • Handling HMRC communication
  • Tax investigation fee protection
  • Advice during compliance checks

Contact Information:

  • Website: www.rpgcrouchchapman.co.uk
  • Email: hello@rpgcc.co.uk
  • Facebook: www.facebook.com/RPGCCAdvisers
  • Twitter: x.com/RPGCCAccounting
  • LinkedIn: www.linkedin.com/company/rpg-crouch-chapman-llp
  • Instagram: www.instagram.com/rpgccadvisers
  • Address: 40 Gracechurch Street, London, EC3V 0BT
  • Phone: 020 7879 9050

Xeinadin

Xeinadin provide a tax investigation service focused on covering professional fees when HMRC opens an enquiry. The service is designed to ensure clients have access to representation without needing to weigh up the cost of engaging advisers once an investigation begins.

Their involvement centres on defending the client’s position during the enquiry and ensuring that responses to HMRC are properly handled. The emphasis is on maintaining a structured approach to dealing with requests and challenges raised during the process.

Key Highlights:

  • Fee protection linked to HMRC enquiries
  • Focus on access to professional representation
  • Support during defence of tax positions
  • Coverage triggered by HMRC investigations
  • Practical handling of enquiry process

Services:

  • HMRC enquiry representation
  • Defence against HMRC investigations
  • Handling HMRC communication
  • Tax investigation fee protection

Contact Information:

  • Website: www.xeinadin.com
  • Email: info@xeinadin.com
  • Facebook: www.facebook.com/xeinadin
  • Twitter: x.com/xeinadin
  • LinkedIn: www.linkedin.com/company/xeinadin
  • Address: Becket House, 36 Old Jewry, Bank, London, EC2R 8DD
  • Phone: 0203 086 8677

Taylor Associates

Taylor Associates deal with tax investigations as part of their wider accountancy services, supporting businesses that are selected for HMRC enquiries. Their involvement typically includes taking control of communication with HMRC and guiding the client through each stage of the process.

Their service includes fee protection, which covers the cost of professional work linked to the investigation. They remain involved through to appeals where required, managing both the practical and technical aspects of the enquiry.

Key Highlights:

  • Support for businesses facing HMRC enquiries
  • Representation throughout investigation and appeal stages
  • Fee protection covering professional costs
  • Handling of HMRC communication
  • Involvement in complex tax matters

Services:

  • HMRC tax enquiry representation
  • VAT and compliance investigations
  • PAYE and NIC enquiries
  • Tax tribunal support
  • Appeals handling
  • Tax investigation fee protection

Contact Information:

  • Website: taylorsllp.com
  • Email: enquiries@taylorsllp.com
  • Address: 1st Floor Gallery Court, 28 Arcadia Avenue, London N3 2FG
  • Phone: 020 3301 9001

Kreston Reeves

Kreston Reeves approach tax investigations through a combination of dispute support and fee protection. Their service covers professional costs linked to HMRC enquiries, allowing them to remain involved from the initial contact through to resolution.

Their work includes handling different types of disputes, from standard enquiries to more technical cases involving residence, fraud concerns or formal HMRC procedures. They also support alternative dispute resolution and cases that proceed to litigation.

Key Highlights:

  • Coverage of professional fees during HMRC enquiries
  • Support from initial contact through to resolution
  • Experience across a range of tax disputes
  • Involvement in formal HMRC procedures
  • Access to legal and dispute resolution support

Services:

  • HMRC tax enquiries
  • Code of Practice 8 and 9 investigations
  • Alternative dispute resolution
  • Appeals and litigation support
  • VAT and employer compliance disputes
  • IR35 and status reviews

Contact Information:

  • Website: www.krestonreeves.com
  • Twitter: x.com/KrestonReeves
  • LinkedIn: www.linkedin.com/company/kreston-reeves
  • Address: 2nd Floor, 168 Shoreditch High Street, London, E1 6RA
  • Phone: +44 (0)20 7382 1820

Markel Tax

Markel Tax specialise in supporting individuals and businesses through HMRC investigations, with a focus on handling complex and sensitive cases. Their team includes former HMRC professionals, which informs how they approach enquiries and disclosure processes.

They are involved at each stage of an investigation, from initial contact through to resolution, including situations where formal disclosure or dispute resolution is required. Their work often includes managing detailed submissions and preparing clients for meetings with HMRC.

Key Highlights:

  • Experience across a wide range of HMRC investigations
  • Team includes former HMRC professionals
  • Involvement in serious cases including fraud enquiries
  • Support through full investigation lifecycle
  • Focus on disclosure and dispute processes

Services:

  • HMRC compliance enquiries
  • Code of Practice 8 and 9 investigations
  • Voluntary disclosures and WDF
  • Alternative dispute resolution
  • Employer compliance enquiries
  • IR35 and status reviews

Contact Information:

  • Website: uk.markel.com
  • Twitter: x.com/MarkelUK
  • LinkedIn: www.linkedin.com/company/markeluk
  • Address: One Snowhill, Birmingham, B4 6GH
  • Phone: 0330 822 3555

Conclusion

Choosing a tax investigation advisor in the UK is not always straightforward, and in many cases it only becomes a priority when an enquiry is already underway. Some organisations look for firms with direct HMRC experience, others focus on how the process will be handled day to day, especially when internal teams are already stretched.

What tends to matter in practice is how clearly the firm can guide the situation – from understanding the scope of the enquiry to managing communication and keeping things moving. In more complex cases, experience with disclosures, disputes or tribunal work can also shape the outcome.

This guide was put together to give a clearer view of the firms operating in this space and how their services are structured. It is not a ranking or recommendation, but a way to understand the different approaches and decide what kind of support fits your situation.