Financial Due Diligence Services Companies in London - Complete Overview
AC
Acumon Chartered Accountants·13 min read
This practical guide walks you through the financial due diligence services companies operating in London and how they help businesses navigate M&A transactions with greater confidence.
Rather than a strict ranking, this is an objective overview designed to give you clear context on who these companies are, how they operate, and the types of clients they typically support.
London is home to a diverse range of financial due diligence companies - from large international players with broad resources to more specialised teams that focus exclusively on transaction support. Each brings different strengths, experience levels, and approaches to analysing corporate structures, cashflow, tax positions, forecasts, and operational risks.
Whether you are preparing to buy or sell a business, understanding these companies will help you identify the right expertise for your specific transaction and make a more informed choice.
Acumon
Acumon is a London-based firm of chartered accountants providing specialist financial due diligence services to buyers, sellers and investors. The company supports mergers, acquisitions, disposals and investment transactions across the UK and internationally. Acumon focuses on delivering clear financial analysis and practical risk insights that help clients make better informed decisions.
The firm works with corporate groups, private equity houses, family offices and owner-managed businesses. Each due diligence engagement is tailored to the size, sector and complexity of the transaction. Acumon combines detailed financial review with commercial understanding gained from its own acquisition experience.
In addition to standard due diligence, the company supports both buy-side and vendor assignments. This allows clients to either validate a target or prepare their business for sale with greater confidence. Acumon’s approach emphasises clear reporting and actionable findings throughout the process.
Due Diligence Capabilities:
Acumon provides financial due diligence services across a wide range of transaction types and client situations. These include:
Buy-side due diligence for acquirers
Vendor due diligence for sellers
Mid-market corporate transactions
Private equity investments and exits
International group subsidiary reviews
SME and owner-managed business deals
Due diligence engagements are led by experienced professionals with direct senior involvement from planning to final reporting.
Regulatory Licences and Registrations:
Acumon operates with the following key professional registrations and compliance standards:
ICAEW chartered accountants registration
Registered audit firm
UK data protection and secure data room compliance
Professional indemnity insurance for transaction services
These registrations support the delivery of reliable due diligence work for both UK and cross-border transactions.
Core Services:
Acumon provides supporting services that strengthen transaction outcomes. These include:
Financial due diligence
Corporate structure and group analysis
Cash flow and working capital review
Forecast and quality of earnings assessment
Tax due diligence
Operational and strategic risk review
Post-transaction support
Due diligence work is often delivered alongside ongoing discussions with management teams and boards regarding key findings and risk mitigation.
Supporting M&A Transactions:
Acumon works with organisations at different stages of the transaction journey. The company supports clients who are:
Preparing for a business acquisition
Planning the sale of their company
Evaluating investment opportunities
Reviewing international subsidiaries
Seeking clarity on financial risks before completion
Early engagement helps ensure potential issues are identified and addressed efficiently.
Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
PwC UK
PwC supports buyers with financial due diligence during acquisition processes. The company examines financial, commercial, operational and strategic assumptions to help validate the rationale behind a potential deal. Their work focuses on understanding past performance to build a realistic view of future prospects and spot any hidden issues.
The approach includes detailed analysis of revenue streams, market conditions, maintainable earnings and future cash flows. PwC also reviews operational matters and potential synergies. This helps corporate and financial buyers gain clearer insight before committing to a transaction. The company works across different deal types and sizes in the London market.
Address: 1 Embankment Place London WC2N 6RH United Kingdom
LinkedIn: www.linkedin.com/company/pwc-uk
Facebook: www.facebook.com/PwCUK
Instagram: www.instagram.com/pwc_uk
EY
EY delivers due diligence through its EY-Parthenon team for mergers and acquisitions. The company combines financial review with commercial, operational and specialist assessments to give clients a rounded view of opportunities and risks. Their process supports both buyers and sellers in London and beyond.
EY examines historical financials, forecast assumptions and value drivers while integrating insights from other areas such as technology and people. The company uses data-driven methods to highlight normalisation adjustments and potential exposures. This integrated style helps clients make decisions with more clarity during transactions.
Key Highlights:
Financial and commercial due diligence
Operational and IT assessment
Buy-side and sell-side support
Data analytics integration
Risk identification focus
Services:
Historical financial analysis
Forecast evaluation
Working capital review
Commercial due diligence
Operational due diligence
IT and technology due diligence
Human resources due diligence
Contact Information:
Website: www.ey.com
Phone: +44 20 7951 2000
Address: 1 More London Place, London SE1 2AF
LinkedIn: www.linkedin.com/company/ernstandyoung
Facebook: www.facebook.com/EY
Twitter: x.com/EYnews
Deloitte
Deloitte provides transaction services with a strong emphasis on financial due diligence for acquisitions and disposals. The company supports both corporate clients and private equity teams throughout the deal process in London. Their teams focus on evaluating risks and opportunities that matter for decision making.
Deloitte works on acquisition due diligence and vendor support to help sellers present information clearly. The company brings together financial analysis with operational and commercial perspectives. This helps clients understand the full picture before completing a transaction.
Key Highlights:
Acquisition and vendor due diligence
Corporate and private equity focus
Integrated transaction support
Risk and opportunity evaluation
Services:
Financial due diligence
Commercial due diligence
Operational review
Working capital analysis
Vendor due diligence
Deal lifecycle support
Contact Information:
Website: www.deloitte.com
Phone: +44 (0)20 7936 3000
Address: 1 New Street Square London, EC4A 3HQ United Kingdom
LinkedIn: www.linkedin.com/company/deloitte
Facebook: www.facebook.com/deloitteuk
Twitter: x.com/deloitteuk
KPMG
KPMG offers deal advisory services that include due diligence for transactions. The company uses sector knowledge and analytical tools to examine targets from multiple angles. Their teams support clients in assessing value, risks and potential in the London market.
KPMG combines financial review with commercial, operational and technology perspectives. The company helps both buyers and sellers prepare for and navigate the due diligence process. Their approach aims to provide practical insights that inform deal decisions and negotiations.
BDO offers transaction services with a focus on due diligence for both buyers and sellers. The company supports clients through mergers, acquisitions, capital raises and other deals. Their work helps identify financial risks and opportunities while providing practical insights for decision making.
The team specialises in the mid-market segment and works with corporates, private equity houses and financial investors. BDO combines financial analysis with commercial and operational perspectives. This approach gives clients a clearer picture of underlying earnings, cash flows and potential issues. They also support post-transaction phases when needed.
Key Highlights:
Buy-side and sell-side due diligence
Mid-market transaction focus
Commercial and operational input
Post-deal support options
Services:
Financial due diligence
Commercial due diligence
Operational due diligence
IT due diligence
ESG due diligence
Working capital analysis
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
Grant Thornton
Grant Thornton provides financial due diligence tailored to acquisition and investment decisions. The company examines historical performance, underlying profitability and key business drivers. Their process highlights trading patterns, working capital and potential red flags.
The team works closely with clients throughout the review and flags important findings early. Grant Thornton combines financial expertise with sector knowledge to support both corporate and private equity transactions in London and across the UK.
Moore Kingston Smith delivers due diligence support for buyers, sellers and investors. The company focuses on mid-market and SME transactions across various sectors. Their specialists provide practical advice throughout the transaction lifecycle.
The team works with trade buyers, private equity and family offices. Moore Kingston Smith helps assess financial risks and opportunities while supporting vendor preparation and negotiation. Their approach emphasises clear, actionable insights for each deal.
Kreston Reeves offers financial due diligence services from its London and South East offices. The company supports buyers, investors and funders with clear and concise reporting. Their reviews focus on performance, cash flows and key transaction risks.
The team tailors the scope to each deal, whether a high-level review or detailed analysis. Kreston Reeves works alongside other specialists when needed and helps clients make informed decisions with practical recommendations.
Key Highlights:
Tailored review scope
London and South East presence
Buyer and investor support
Practical recommendation focus
Services:
Pre-acquisition due diligence
Vendor due diligence
Pre-investment due diligence
Pre-lend due diligence
Financial performance review
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
PKF Littlejohn
PKF Littlejohn provides due diligence and advisory support for mergers, acquisitions, fund raises and sales. The company works with both experienced and newer leadership teams across London, Leeds and Manchester. Their process identifies risks and opportunities to support strategic decisions throughout the transaction.
The team delivers financial, tax, IT, ESG and regulatory due diligence with a hands-on approach. PKF Littlejohn also offers vendor support, transaction readiness reviews and completion accounts assistance. This helps clients prepare effectively and manage the deal from start to finish with clear insights.
Address: 15 Westferry Circus, Canary Wharf, London E14 4HD
Twitter: x.com/PKF_Littlejohn
LinkedIn: www.linkedin.com/company/littlejohn
Instagram: www.instagram.com/pkf.littlejohn
Rayner Essex
Rayner Essex offers financial due diligence services from offices in London and Hertfordshire. The company supports both buyers and sellers with reviews of financial records, cash flows and projections. Their process helps parties understand the full picture during transactions.
The team works across different business sizes from sole traders to larger corporates. Rayner Essex provides a dedicated senior contact and focuses on clear communication. This makes the due diligence process more straightforward for clients preparing to buy or sell.
Address: Tavistock House South, Tavistock Square, London, WC1H 9LG
LinkedIn: www.linkedin.com/company/rayner-essex
Facebook: www.facebook.com/rayneressexllp
Twitter: x.com/rayneressexllp
Instagram: www.instagram.com/rayneressex
Saffery
Saffery provides transaction services that include financial due diligence for acquisitions and sales. The company focuses on quality of earnings, working capital and debt analysis to give clients clearer deal insights. Their support covers both buy-side and vendor perspectives.
The team works with SMEs and owner-managed businesses across various sectors. Saffery delivers tailored reviews and vendor assistance to help address issues early. This helps reduce surprises and supports smoother transaction outcomes.
Address: 71 Queen Victoria Street, London EC4V 4BE, UK
LinkedIn: www.linkedin.com/company/saffery
Instagram: www.instagram.com/saffery_uk
Mercer & Hole
Mercer & Hole supports clients with corporate finance and due diligence work as part of their wider services. The company advises on business acquisitions and provides insights into financial matters during transactions. Their London office serves clients considering purchases or sales.
The team delivers practical advice focused on understanding the financial position and potential risks in deals. Mercer & Hole works with businesses across different sectors and helps clients review information before completing transactions. This approach supports informed decision making throughout the process.
S&W Group provides financial due diligence during transactions to give insights into past performance and future projections. The company identifies risks and helps clients understand key financial aspects before deals complete. Their work covers both buy-side and vendor situations.
The team tailors the scope to client needs and delivers clear findings on earnings, cash flows and controls. S&W also supports financing arrangements and offers SPA advice alongside due diligence. This helps clients make decisions with better information across various transaction types.
Barnes Roffe delivers financial due diligence to support business acquisitions and investment decisions. The company reviews historical results, forecasts and financial position to highlight potential risks. Their process aims to give buyers clearer understanding before purchase.
The team tailors reviews to the target company and funder requirements when needed. Barnes Roffe examines cash flows, assets, liabilities and accounting policies. This helps reduce surprises and supports negotiations during the acquisition process.
Light HC offers due diligence and financial analysis services for investment and transaction decisions. The company provides detailed evaluations of financial information and business opportunities. Their work supports clients considering mergers, acquisitions or strategic moves.
The team focuses on risk identification and validation of financial data through balance sheet and cash flow reviews. Light HC delivers clear reports with actionable insights tailored to each engagement. This approach helps clients proceed with greater clarity on potential investments.
Address: Fitzrovia, 60 Tottenham Court Road, London, W1T 2EW
RPG Crouch Chapman
RPG Crouch Chapman delivers buy-side and sell-side due diligence from its London office. The company provides insights into quality of earnings, working capital and cash flows for mid-market transactions. Their team supports private equity, corporates and lenders with clear findings.
The approach includes full scope or red-flag reviews depending on client needs. RPG Crouch Chapman maintains regular communication during engagements and offers vendor due diligence and SPA support. This helps clients understand risks and opportunities within agreed timescales.
Choosing the right financial due diligence services company in London depends on several practical factors. These include the size and complexity of the transaction, the sector involved, the maturity of the target’s processes, and any specific regulatory requirements. Some companies offer a fully integrated multidisciplinary approach, while others provide more focused, specialist input on financial risks and controls.
The right partner delivers independent assurance and practical steps to reduce risks and support resilience. Ultimately, this guide offers a neutral overview of how different companies operate so you can compare them more effectively. With clearer context, it becomes easier to identify the team that best matches your transaction needs and working style.
AC
Written by the Acumon team
Acumon is an ICAEW-registered firm of chartered accountants and registered auditors
based in London, with offices in Pitstone, Aylesbury and Bournemouth. Need advice on
anything covered here? Talk to us.
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