Due Diligence Firms in London: A Practical Guide

Choosing a due diligence provider in London is rarely just a box-ticking step before a deal. A good review can help buyers, investors, lenders, and leadership teams understand what they are really looking at before money, time, or reputation is put at risk.

London has a broad due diligence market, with global advisory networks, specialist transaction firms, legal and financial consultancies, and sector-focused teams all working in this space. Some providers focus on financial and tax due diligence, while others support commercial, legal, operational, technical, ESG, or regulatory reviews. The right fit often depends on the type of transaction, the size of the business, and how much depth the review needs.

This guide looks at a selection of due diligence services companies operating in London. It is not meant to rank providers or present one firm as the obvious choice. The aim is more practical: to give a clearer view of who these companies are, what kinds of clients they typically support, and where their due diligence work tends to be most relevant.

Acumon

Acumon is a UK firm of chartered accountants and registered auditors that supports companies, charities, regulated entities, and international corporate groups with due diligence, audit, financial reporting, governance, and risk-related work.

In due diligence, the value of this background is quite practical. Transaction reviews rarely depend on one document or one set of accounts. They usually require a closer look at how financial information is prepared, how records are organised, how controls work, and whether the structure of the business is clear enough for investors, buyers, lenders, or boards to make informed decisions. Acumon works with organisations ranging from growing owner-managed businesses and charities through to larger corporate groups and regulated entities.

Acumon holds a Public Interest Entity (PIE) audit licence, which allows the firm to audit listed companies and other entities that fall under enhanced regulatory oversight in the United Kingdom. This matters for due diligence because some transactions involve organisations where reporting standards, governance expectations, and regulatory scrutiny are higher than usual. PIE audits are subject to additional supervision and quality requirements, and only a limited number of firms are authorised to carry out this type of work.

The firm also holds audit licences in several international financial centres, including the Cayman Islands, British Virgin Islands (BVI), Jersey, and Isle of Man. These registrations give Acumon a stronger base for supporting international corporate groups, especially where a review involves entities spread across more than one jurisdiction.

Cross-border group structures can be fairly layered. A UK operating company may sit alongside offshore holding companies, investment vehicles, or subsidiaries in other locations, particularly in sectors such as investment management, technology, energy, and international trade. In due diligence, this can make the review more complex, as the work may need to consider group accounts, ownership links, related-party balances, reporting flows, and how financial information is consolidated.

Acumon works with finance teams, boards, investors, and management teams on reviews connected to transactions, investment, restructuring, and group-level financial assessment. Their work can also help organisations identify weaknesses in reporting processes, governance arrangements, internal controls, and documentation before these issues become more difficult to manage during a transaction.

Due Diligence Capabilities

Acumon provides due diligence support for organisations with different legal structures, reporting needs, and levels of regulatory oversight. 

These include:

• UK limited companies and corporate groups
• Public Interest Entities (PIEs) and regulated organisations
• UK subsidiaries of international groups
• charities and not-for-profit organisations
• owner-managed businesses approaching statutory audit thresholds
• offshore holding companies and investment vehicles

Due diligence work is usually led or closely reviewed by senior professionals who understand both the numbers and the practical issues behind them. 

Regulatory Licences and Registrations

Acumon holds audit registrations that allow the firm to work with organisations operating in the UK and in several international financial centres. For due diligence, this is especially relevant where a transaction involves offshore entities, regulated structures and group accounts.

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 allow Acumon to support groups with entities in the UK and key offshore jurisdictions. In a due diligence context, that can be useful when financial review needs to take account of local reporting rules, group consolidation, and holding structures.

Core Services

Alongside statutory audit work, Acumon provides services that help organisations review financial information, understand risk, and prepare for decisions linked to investment, acquisition, sale, or restructuring.

These include:

• financial due diligence
• transaction-related financial review
• 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

Their due diligence work may involve discussions with management, boards, investors, lenders, or finance teams about the quality of available information, the strength of reporting processes, and any issues that could affect a transaction. 

Companies often need this type of support before raising investment, acquiring another business, preparing for sale, reviewing a group structure, or expanding internationally.

Acumon works with businesses that are:

• preparing for external investment
• reviewing a potential acquisition
• entering a sale or transaction process
• expanding into international markets
• operating within corporate group structures
• working with offshore holding companies or investment vehicles
• strengthening reporting before investor or lender review

Engaging Acumon early can help organisations prepare their financial information, supporting records, governance documents, and internal processes before a formal due diligence review begins.

Contact Information

• Website: acumon.com
• Phone: 020 8567 3451
• E-mail: mail@acumon.com
• Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK

perfORM Due Diligence Services

perfORM Due Diligence Services is a London-headquartered provider focused on operational due diligence for the investment management market. Their work is aimed at allocators, investment managers, third-party service providers, and other organisations that need a clearer view of operational risk before making or supporting investment decisions.

Their services cover both sides of the due diligence process. For allocators, they provide operational risk assessments across different asset classes. For investment managers, they offer support in preparing for institutional operational due diligence reviews. perfORM also works on service provider due diligence, background checks, and report-based solutions that help clients monitor risk, compare options, and respond to regulatory or investor expectations without turning the process into a purely formal exercise.

Key Highlights:

• Specialises in operational due diligence for investment-related decisions
• Works with allocators, investment managers, and service providers
• Covers a wide range of asset classes and investment structures
• Provides both one-off reviews and ongoing monitoring support
• Includes background checks at individual and entity level
• Uses due diligence reporting to support selection and oversight

Services:

• Allocator on-demand operational due diligence
• Investment manager ODD therapy
• Operational due diligence report solutions
• Third-party service provider due diligence
• Enhanced background checks
• Ongoing operational risk monitoring
• Manager selection support
• Operational risk assessment

Contact information:

• Website: performdd.com
• Phone: +44 (0) 203 746 8974
• E-mail: info@performdd.com
• Address: The Scalpel, 18th Floor, 52 Lime Street, London, EC3M 7AF
• Linkedin: www.linkedin.com/company/performdd

Ergo Strategy Group

Ergo Strategy Group provides due diligence services with a strong focus on material risks, liabilities, and opportunities linked to environmental, social, governance, regulatory, and institutional factors. Their work is built around gathering reliable information so that clients can make better decisions in transactions, compliance reviews, or wider performance improvement work.

Ergo Strategy Group works with private companies, governments, and donor organisations, with particular experience in natural resource industries. Their due diligence process can cover social, economic, environmental, labour, regulatory, and institutional issues, depending on the target asset and the purpose of the review. They also adapt the scope of each assignment around the specific concerns of the client, which is useful when due diligence needs to go beyond standard financial or legal checks.

Key Highlights:

• Focuses on risk, liability, and opportunity assessment
• Provides ESG-related due diligence support
• Works with private companies, governments, and donor organisations
• Has experience in natural resource industries
• Covers social, environmental, labour, and regulatory issues
• Offers clear findings and practical recommendations

Services:

• Due diligence
• ESG due diligence
• Risk and opportunity assessment
• Compliance review
• Environmental and social review
• Labour and regulatory assessment
• Project feasibility support
• Political risk analysis

Contact information:

• Website: ergostrategygroup.com
• Phone: +44 7723 509682
• E-mail: info@ergostrategygroup.com
• Address: 167-169 Great Portland Street, 5th Floor, London, W1W 5PF, United Kingdom
• Twitter: x.com/ErgoStrategy
• LinkedIn: www.linkedin.com/company/ergo-strategy-group

S&W

S&W provides financial due diligence services as part of its corporate finance and transaction support work. S&W focuses on helping clients understand a business’s past performance, projected performance, working capital position, cash flows, internal controls, tax matters, and transaction-related risks before a deal moves forward.

S&W works across buy-side and vendor-side situations, as well as financing, refinancing, pre-bid, and post-bid support. Their due diligence work is built around agreeing a clear scope with the client, so the review focuses on the areas that matter most to the transaction. This can include a broad financial review or a more targeted assignment, depending on the deal stage and the questions that need answering.

Key Highlights:

• Supports financial due diligence for transactions
• Covers buy-side and vendor-side situations
• Reviews past performance, forecasts, cash flows, and working capital
• Includes tax, pensions, IT, and internal control considerations
• Provides support around sale and purchase agreements
• Offers tailored assignments for specific deal needs

Services:

• Financial due diligence
• Financial investigations
• Sale and purchase agreement advice
• Completion accounts support
• Tax due diligence
• Tax structuring
• Vendor due diligence and vendor assistance
• Pre-bid and post-bid support
• Sector analysis

Contact information:

• Website: www.swgroup.com
• Phone: +44 117 233 2200
• Address: 45 Gresham Street, London EC2V 7BG. 
• Twitter: x.com/S_W_Group
• LinkedIn: www.linkedin.com/company/swgroupuk

Kreston Reeves

Kreston Reeves provides financial due diligence services for buyers, investors, sellers, and funders. Kreston Reeves focuses on reviewing the financial and operational information behind a transaction, so clients can understand the risks, opportunities, and key assumptions before making a decision. Their work is especially relevant where a deal needs clear reporting rather than a long document that is hard to use.

Kreston Reeves tailors the scope of each review around the transaction. Some clients may need a high-level overview, while others may need a deeper review of historic performance, current trading, cash flows, balance sheet items, earnings quality, and forecast assumptions. Their corporate finance team also works with corporate tax specialists and can connect with international colleagues through the Kreston Global network when a transaction involves overseas subsidiaries or branches.

Key Highlights:

• Provides financial due diligence for buyers, sellers, investors, and funders
• Covers pre-acquisition, pre-investment, pre-lend, and vendor due diligence
• Reviews financial performance, cash flows, forecasts, and key risks
• Tailors reports to the needs of each transaction
• Works with corporate tax specialists on tax due diligence
• Supports transactions with international considerations through a global network

Services:

• Financial due diligence
• Vendor due diligence
• Pre-acquisition due diligence
• Pre-investment due diligence
• Pre-lend due diligence
• Tax due diligence support
• Corporate finance support
• Business valuations

Contact information:

• Website: www.krestonreeves.com
• Phone: +44 (0)330 124 1399
• Address: 2nd Floor, 168 Shoreditch High Street, London, E1 6RA
• Twitter: x.com/KrestonReeves
• LinkedIn: www.linkedin.com/company/kreston-reeves

Greyhawk

Greyhawk provides enhanced due diligence for investment targets, business partners, acquisition targets, and other parties where reputation, integrity, and financial crime risk need closer review. Greyhawk looks at both companies and key individuals, including ownership, corporate history, market position, management background, business interests, and possible reputation concerns.

Greyhawk’s work is relevant for legal, risk, compliance, M&A, investment banking, investor, private equity, and development finance teams. Their due diligence combines public-source research with confidential enquiries, which can be useful when standard checks raise red flags but do not fully explain the issue. The focus is not only on whether a company looks suitable on paper, but also on the people, relationships, and events that may affect a transaction or partnership later.

Key Highlights:

• Focuses on enhanced due diligence and reputational risk
• Reviews both companies and key individuals
• Supports M&A, investment, legal, compliance, and risk teams
• Covers fraud, corruption, money laundering, and selected ESG risks
• Uses public-source research and confidential enquiries
• Works across developed, emerging, and complex markets

Services:

• Enhanced due diligence
• Reputational due diligence
• Investment target reviews
• Business partner background checks
• Management and owner integrity checks
• Financial crime risk review
• KYC red flag investigation
• Commercial intelligence
• Confidential enquiries
• Public-source intelligence research

Contact information:

• Website: www.greyhawk-uk.com
• Phone: +44 (0)20 7406 7510
• E-mail: mail@greyhawk-uk.com
• Address: Holborn Gate, 26 Southampton Buildings, London WC2A 1AN
• LinkedIn: www.linkedin.com/company/greyhawk-intelligence-group

Lighthouse Consultants

Lighthouse Consultants provides due diligence and financial analysis services for companies considering investments, mergers, acquisitions, or wider strategic decisions. Lighthouse Consultants focuses on checking financial information, identifying risks, and giving clients a clearer view of the business or opportunity they are assessing.

Their work covers investment reviews, M&A due diligence, risk identification, financial statement analysis, and reporting. This type of support can be useful when a company needs independent validation of information provided by another party, or when a decision depends on understanding financial performance, possible liabilities, and operational or regulatory concerns before moving ahead.

Key Highlights:

• Provides due diligence and financial analysis services
• Supports investment, merger, and acquisition decisions
• Reviews financial information provided by third parties
• Looks at financial, operational, and regulatory risks
• Analyses financial statements and business performance
• Prepares reports to support business decision-making

Services:

• Due diligence
• Financial analysis
• Investment reviews
• Merger and acquisition due diligence
• Risk identification
• Financial statement analysis
• Financial health review

Contact information:

• Website: lighthc.london
• Phone: +44 2078710485
• E-mail: info@lighthc.london
• Address: Fitzrovia, 60 Tottenham Court Road, London, W1T 2EW

London Political Risk Analysis

London Political Risk Analysis provides due diligence services built around background research, corporate affiliation mapping, political exposure checks, and reputation assessment. London Political Risk Analysis focuses on intelligence-led reviews for clients dealing with potential partners, investments, or affiliations in markets where information may be harder to verify through standard sources.

Their team works across linguistic and cultural boundaries, with particular attention to the Middle East, North Africa, and West Africa. This makes their due diligence work relevant for organisations assessing partnerships or operations in complex jurisdictions. The review process draws on regional sources, OSINT, and investigative tools to identify risk indicators that may not be obvious from basic company records or surface-level checks.

Key Highlights:

• Provides intelligence-led due diligence
• Reviews business partners, investments, and affiliations
• Maps corporate links and ownership connections
• Assesses political exposure and reputation risk
• Uses regional sources, OSINT, and investigative tools
• Focuses on complex and high-risk jurisdictions

Services:

• Due diligence
• Business partner vetting
• Background checks
• Corporate affiliation mapping
• Political exposure assessment
• Reputation risk review
• OSINT research
• Regional source research

Contact information:

• Website: www.londonpra.co.uk
• Phone: +44 (0) 20457 28181
• Address: Office One, 1 Coldbath Square, Farringdon, London, EC1R 5HL
• Twitter: x.com/London_PRA
• LinkedIn: www.linkedin.com/company/london-political-risk-analysis-london-pra
• Instagram: www.instagram.com/london_pra

TenIntelligence

TenIntelligence provides due diligence, enhanced due diligence, investigation, and protection services for clients that need a closer view of people, companies, and possible risk exposure. TenIntelligence works with firms under FCA supervision, as well as Nominated Advisors, corporate finance teams, and private equity companies acting for AIM and FTSE listed businesses. Their due diligence work is often linked to director checks, beneficial owner reviews, regulatory expectations, and anti-corruption or anti-money laundering requirements.

TenIntelligence’s approach combines desk-based background checks with wider investigative insight when a basic review is not enough. This can be useful where a candidate, business partner, or transaction party appears clear on paper, but still needs a more careful review of professional history, regulatory exposure, financial background, sanctions, media coverage, or conduct-related concerns. For London-based transactions and regulated environments, their work sits in the more investigative side of due diligence.

Key Highlights:

• Supports enhanced due diligence for regulated firms
• Works with corporate finance and private equity clients
• Reviews directors, board candidates, and beneficial owners
• Covers FCA-related and London Stock Exchange-related requirements
• Looks at financial, regulatory, sanctions, insolvency, and media exposure
• Combines background checks with wider investigative insight

Services:

• Enhanced due diligence
• Background checks
• Director due diligence
• Beneficial owner checks
• FCA compliance-related due diligence
• AIM and FTSE-related checks
• Anti-corruption review

Contact information:

• Website: tenintel.com
• Phone: +44 20 3633 8398
• E-mail: info@tenintel.com
• Address: 18 King William Street, London, EC4N 7BP
• Facebook: www.facebook.com/TenIntelligence
• Twitter: x.com/TenIntelligence
• LinkedIn: www.linkedin.com/company/tenintel
• Instagram: www.instagram.com/TenIntelligence

TRC

TRC provides environmental due diligence and transaction advisory support for clients assessing business operations, assets, or investment risks. TRC’s work is relevant where a transaction may involve environmental liability, site history, regulatory compliance, hazardous materials, waste handling, or operational risks that could affect the value or continuity of a business.

TRC’s due diligence process can include environmental site assessment, limited compliance review, site visits, discussions with site teams, and review of regulatory information. Their work is especially useful in technical or manufacturing-related deals, where the environmental side is not just a legal formality. It can affect operations, future costs, and the level of risk a buyer or investor is taking on.

Key Highlights:

• Focuses on environmental due diligence
• Supports transaction-related risk review
• Assesses contaminated land and environmental compliance issues
• Reviews hazardous materials, waste handling, and site operations
• Works with legal teams and corporate clients on investment-related matters
• Connects technical findings with practical risk management options

Services:

• Environmental due diligence
• Phase I Environmental Site Assessment
• Environmental compliance review
• Contaminated land risk assessment
• Regulatory information review
• Site visit and operational review
• Hazardous materials assessment
• Waste management review

Contact information:

• Website: www.trccompanies.com
• Phone: +44 033.3772.2990                                
• Address: 20 Red Lion Street, 1.13, 1.14, 1.18, London, WC1R 4PQ, United Kingdom
• LinkedIn: www.linkedin.com/company/trc-companies-inc
• Instagram: www.instagram.com/trc_companies

OMMAX

OMMAX provides commercial due diligence for buy-side and sell-side transactions, with a focus on market position, business model quality, growth potential, and commercial risk. OMMAX works with investors, private equity firms, family offices, and sellers that need a clearer view of how a target business performs in its market and whether its growth story is realistic.

OMMAX’s commercial due diligence looks beyond historic performance and examines the business from several angles, including strategy, revenue streams, customer behaviour, competitors, technology, data, and future growth options. Their work is useful when a transaction depends not only on the numbers, but on whether the market, customers, and operating model can support the plan after the deal.

Key Highlights:

• Provides commercial due diligence for buy-side and sell-side transactions
• Reviews business models, revenue streams, and strategic positioning
• Analyses customers, competitors, markets, and growth drivers
• Looks at operational readiness and value creation potential
• Includes technology, data, and AI-related market intelligence
• Links commercial findings with practical risk and growth planning

Services:

• Commercial due diligence
• Buy-side due diligence
• Sell-side due diligence
• Business model analysis
• Strategy analysis
• Customer and revenue analysis
• Market and competitor analysis
• Business plan validation
• Technology and data assessment

Contact information:

• Website: www.ommax.com
• Address: 34 Brook Street , W1K 5DN, London, United Kingdom
• LinkedIn: www.linkedin.com/company/ommax
• Instagram: www.instagram.com/ommax_digital

Moore Kingston Smith

Moore Kingston Smith provides due diligence services through its corporate finance and transaction services team. Moore Kingston Smith works with buyers, investors, and sellers that need a clearer view of transaction risks and opportunities before a deal moves forward. Their work is mainly connected to business purchases, investments, disposals, funding activity, and other transaction points where financial and operational detail needs proper review.

Moore Kingston Smith has a clear focus on mid-market and SME transactions, with sector experience across areas such as media and technology, education, business services, manufacturing, and distribution. Their due diligence support can run from heads of terms through to post-completion, which makes the work relevant not only before a deal is signed, but also when the details need to be checked, negotiated, and followed through after completion.

Key Highlights:

• Supports buyers, investors, and vendors during transactions
• Focuses on mid-market and SME due diligence work
• Covers the transaction process from heads of terms to post-completion
• Works across sectors including media, technology, education, and business services
• Provides practical review of transaction risks and opportunities
• Connects due diligence with tax, ESG, IT, and employee-related review areas

Services:

• Acquisition due diligence
• Vendor due diligence
• Vendor assistance
• Tax due diligence
• SPA advisory and negotiation support
• ESG reporting due diligence
• IT due diligence

Contact information:

• Website: mooreks.co.uk
• Phone: +44 (0)20 4582 1000
• Address: 6th Floor, 9 Appold Street, London, EC2A 2AP
• Twitter: x.com/MooreKSLLP
• LinkedIn: www.linkedin.com/company/moore-kingston-smith

RPG Crouch Chapman

RPG Crouch Chapman provides buy-side and sell-side due diligence services through its corporate finance team in London. RPG Crouch Chapman works with private equity firms, corporates, lenders, and other transaction parties that need to understand the value, risks, and financial position of a target business before making a decision.

Their approach can be adapted depending on the transaction. Some clients may need a full-scope due diligence review, while others may only need a red-flag or key-issues report. RPG Crouch Chapman also puts emphasis on regular communication during the engagement, so key risks are raised as they appear rather than left until the final report. Their work covers financial, tax, vendor-side, and SPA-related support, with experience across sectors such as healthcare, education, logistics, professional services, retail, manufacturing, and property.

Key Highlights:

• Provides buy-side and sell-side due diligence
• Supports private equity, corporate, and lender-led transactions
• Offers full-scope reviews and red-flag reporting
• Reviews earnings, working capital, debt, forecasts, and cash flows
• Provides tax due diligence across main tax areas
• Supports SPA review and completion-related negotiations

Services:

• Financial due diligence
• Tax due diligence
• Vendor due diligence
• SPA assistance and support
• Quality of earnings review
• Working capital review
• Net cash and debt assessment
• Historical trading review
• Forecast review

Contact information:

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

BDO

BDO provides transaction services and due diligence support for companies, investors, private equity funds, and banking institutions. BDO works on transactions such as mergers and acquisitions, listings, delistings, take-private processes, and capital raising. Their due diligence work is used to review the financial, commercial, operational, tax, IT, ESG, and other deal-related areas that can affect value and risk.

BDO supports clients across different stages of a transaction, from early deal review through to post-completion work. Their due diligence can be combined with related advisory services, including valuation, SPA support, bid support, transaction structuring, integration planning, technology risk assessment, and operational performance advice. This makes their section relevant for companies that need more than one narrow review and want transaction support across several workstreams.

Key Highlights:

• Provides transaction services and due diligence for deal-related decisions
• Supports M&A, listings, delistings, capital raising, and take-private activity
• Works with corporates, financial investors, private equity funds, and banks
• Covers financial, commercial, operational, tax, IT, and ESG due diligence
• Supports clients before, during, and after transaction completion
• Connects due diligence with valuation, SPA, bid support, and post-transaction work

Services:

• Commercial due diligence
• ESG due diligence
• Financial due diligence
• IT due diligence
• Operational due diligence
• Tax due diligence and structuring
• Post-transaction support
• Sale and purchase agreement support

Contact information:

• Website: www.bdo.co.uk
• Phone: 020 7486 5888
• Address: 55 Baker Street, London, W1U 7EU, United Kingdom
• LinkedIn: www.linkedin.com/company/bdo-llp
• Instagram: www.instagram.com/bdo_uk

Conclusion

Choosing a due diligence services company in London usually starts with one simple question: what exactly needs to be checked before the decision is made? For some organisations, the main concern is financial performance, working capital, tax exposure, or deal structure. For others, the bigger issue may be operational risk, environmental liability, commercial growth, ESG factors, political exposure, background checks, or the reliability of people connected to the transaction.

That is why the right provider is not always the biggest name or the firm with the longest service list. It depends on the type of deal, the level of risk, the sector, the jurisdictions involved, and how much detail the organisation needs before moving forward. A private equity buyer, a lender, a corporate board, and a company preparing for sale may all need due diligence, but not always the same kind of review.

This guide is meant to make that choice a little easier. It brings together different types of due diligence companies operating in London, from financial and transaction advisory firms to investigative, ESG, commercial, operational, and risk-focused providers. The aim is not to rank them, but to show how their work differs and where each type of firm may fit into a transaction or business review.

For organisations comparing providers, the useful next step is to look at the scope first, not the label. A good due diligence partner should be able to explain what they will review, what they will not cover, how findings will be reported, and how their work will support the final decision. In a city with such a wide advisory market, that clarity matters. It helps businesses avoid a generic review and choose a firm that matches the real questions behind the deal.