Vendor Due Diligence Companies in the UK: Firms and Services Guide
AC
Acumon Chartered Accountants·16 min read
Selling a business or preparing for investment often involves more than presenting strong financial results. Buyers and investors want confidence in the information they receive, making vendor due diligence an important part of many transactions. A well-prepared review can help identify potential issues early, support a smoother sale process and reduce the likelihood of unexpected questions during negotiations.
The UK has a broad market of firms offering vendor due diligence services, ranging from global professional services networks to independent corporate finance and advisory practices. While many provide similar core services, their experience, sector focus and approach to transaction support can differ significantly depending on the size and complexity of the deal.
This guide highlights a selection of organisations providing vendor due diligence services in the UK. Rather than ranking providers, the aim is to offer practical context on the firms operating in this area, the types of clients they typically support and the wider transaction advisory services they offer. It is intended as a starting point for businesses exploring their options before engaging an adviser.
Acumon
Acumon is a UK firm of chartered accountants and advisors providing vendor due diligence services to businesses across the UK.
The firm works with owner-managed businesses, corporate groups, shareholders and UK subsidiaries of international organisations preparing for business sales, investments or corporate transactions. Vendor due diligence helps businesses identify potential issues before a transaction, improving preparedness and supporting a smoother sale process.
Acumon provides vendor due diligence services as part of its wider accounting, tax and advisory offering. The firm supports clients with financial reporting, tax advisory, statutory accounts, transaction support and business planning, helping organisations prepare reliable financial information for prospective purchasers.
Acumon holds a Public Interest Entity (PIE) audit licence, enabling the firm to support organisations subject to enhanced regulatory oversight in the United Kingdom. In addition to its UK statutory audit registration, the firm also maintains audit licences in the Cayman Islands, British Virgin Islands (BVI), Jersey and Isle of Man. These licences enable the firm to support organisations operating across multiple jurisdictions.
Vendor due diligence enables businesses to assess financial, tax and commercial matters before entering a transaction. Early identification of issues can help reduce transaction risk, improve the efficiency of the sale process and support informed negotiations with potential buyers. Vendor due diligence is commonly undertaken as part of mergers and acquisitions, management buy-outs and other corporate transactions.
Acumon works with business owners, directors and finance teams to support vendor due diligence engagements while helping organisations strengthen financial reporting, governance, internal controls and strategic decision-making.
Vendor Due Diligence Capabilities
Acumon provides vendor due diligence services across a wide range of organisational structures and sectors.
These include:
UK companies and corporate groups
owner-managed businesses and growing companies
UK subsidiaries of international groups
businesses preparing for corporate transactions
organisations operating across multiple jurisdictions
companies planning ownership changes
Vendor due diligence engagements are typically led by experienced professionals with direct involvement throughout the engagement.
Regulatory Licences and Registrations
Acumon holds several audit registrations that enable it to support organisations operating 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 allow the firm to support organisations operating across both the UK and key international financial centres.
Core Services
In addition to vendor due diligence services, Acumon provides a range of accounting, tax and advisory services.
These include:
transaction support
statutory external audit
group and subsidiary audits
Public Interest Entity (PIE) audits
charity and not-for-profit audit
internal audit and governance reviews
risk management and compliance support
Vendor due diligence work is often delivered alongside discussions regarding business sales, acquisitions, restructuring, financial reporting and transaction planning.
Many organisations seek professional advice before commencing a sale process to improve transaction readiness, address potential issues and provide buyers with reliable financial information.
Acumon works with organisations that are:
preparing for a business sale
planning a corporate transaction
reviewing their financial position
restructuring their business
responding to buyer enquiries
planning for future growth
Early engagement can help businesses identify issues before a transaction, improve financial transparency and support a more efficient sales process.
Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
Phone: 020 8567 3451
S&W
S&W is a UK firm of chartered accountants and business advisers that includes vendor due diligence within its wider transaction services offering. Their approach is designed to support businesses preparing for a sale by reviewing financial and tax information before it is shared with potential buyers. This gives sellers an opportunity to examine key areas of the business in advance and address issues that could affect the transaction process.
The firm offers both full vendor due diligence and vendor assistance, depending on the scope and objectives of the sale. Vendor due diligence reports are prepared for use by prospective purchasers, while vendor assistance provides a more focused review for the seller's own planning. Alongside transaction services, S&W can draw on specialists in tax, employee benefits, digital services and other advisory areas when a transaction involves more complex regulatory or cross-border considerations.
Key Highlights
UK firm offering vendor due diligence within transaction services
Supports mergers, acquisitions and business disposals
Offers vendor due diligence and vendor assistance
Reviews financial and tax information before buyer due diligence
Access to tax and specialist advisory teams
Experience across UK and cross-border transactions
Services
Vendor due diligence
Vendor assistance
Financial due diligence
Sale and purchase agreement advice
Financial modelling
Value creation advisory
Transaction tax support
Cross-border transaction advisory
Contact Information
Website: www.swgroup.com
Twitter: x.com/S_W_Group
LinkedIn: www.linkedin.com/company/swgroupuk
Address: 45 Gresham Street, London EC2V 7BG
Phone: +44(0)204 617 55 00
Grant Thornton
Grant Thornton includes vendor due diligence within its transaction advisory services, supporting businesses that are preparing for a sale or investment process. The firm focuses on helping sellers organise financial information before potential buyers begin their own review. This approach allows management teams to identify issues early, present consistent information to multiple bidders and reduce disruption during the transaction.
Alongside vendor due diligence, Grant Thornton offers vendor assist services for transactions where a lighter level of support is more appropriate. Their transaction specialists work with finance teams throughout the sales process, combining financial analysis with input from tax and sector specialists where needed. The aim is to give buyers a clear understanding of the business while helping sellers manage the flow of information and maintain momentum during negotiations.
Key Highlights
UK transaction advisory firm
Vendor due diligence and vendor assist services
Supports controlled business sale processes
Reviews financial information before buyer due diligence
Menzies approaches vendor due diligence as part of the preparation for a business sale, helping sellers examine financial performance and key transaction risks before approaching the market. The process is centred on producing an independent review that gives prospective buyers a clearer picture of the business while allowing management to deal with potential issues at an earlier stage.
The firm's deal advisory team covers the full vendor due diligence process, from planning the scope of the review through to preparing a report for potential purchasers. Financial performance, adjusted EBITDA, working capital, debt and key commercial considerations all form part of the assessment. This supports a more structured sale process and helps management respond to buyer enquiries using consistent financial information.
Key Highlights
Vendor due diligence within deal advisory services
Independent financial reviews for business sales
Focus on earnings quality and transaction risks
Supports management throughout the sale process
Reviews tailored to individual transactions
Corporate finance and valuation expertise available
Saffery includes vendor due diligence within its transaction services, helping business owners prepare for a sale before discussions with potential buyers begin. The review focuses on the financial position of the business, giving sellers an opportunity to identify issues early and present information in a clear and consistent way throughout the transaction.
Alongside financial due diligence, the firm can carry out tax reviews, vendor assistance and bid support where these form part of the transaction. Its transaction team works across different sectors, with each engagement shaped around the business being sold and the stage of the deal. The overall process is intended to reduce disruption, support informed negotiations and help buyers assess the business using independently reviewed financial information.
Address: Midland House, 2 Poole Road, Bournemouth, Dorset BH2 5QY, UK
Phone: +44 (0)1202 204744
Forvis Mazars
Forvis Mazars offers vendor due diligence and vendor assistance as part of its financial advisory practice. The firm supports sellers throughout the preparation stage of a transaction, helping management organise financial information, identify areas that may attract buyer attention and prepare documentation before detailed discussions begin.
The scope of support can range from vendor assistance for the seller's own use to full vendor due diligence reports that are shared with prospective purchasers. In addition to financial analysis, the team assists with data room preparation and transaction planning, drawing on experience from both buy-side and sell-side engagements to support a structured sales process.
Key Highlights
Vendor due diligence within financial advisory services
Vendor assistance for business disposals
Supports data room preparation
Reviews financial information before sale
Experience across buy-side and sell-side transactions
Address: 3 Chamberlain Square, Birmingham, B3 3AX, United Kingdom
Phone: +44 (0) 121 232 9500
Mercer & Hole
Mercer & Hole includes vendor due diligence and vendor assistance within its corporate advisory services for businesses preparing for a sale or disposal. The firm helps sellers review financial information before engaging with buyers, allowing potential issues to be identified early and giving management more control over how the transaction is presented.
Its approach covers both full vendor due diligence and vendor assistance, depending on the nature of the transaction. Vendor due diligence reports are prepared for prospective purchasers, while vendor assistance is aimed at supporting the seller throughout the process. Senior corporate advisory specialists remain involved from planning through to completion, helping businesses manage buyer enquiries and maintain momentum during negotiations.
Key Highlights
Vendor due diligence within corporate advisory
Offers vendor due diligence and vendor assistance
Supports businesses preparing for sale
Focus on early identification of transaction risks
Senior advisers involved throughout the process
Reviews designed for sellers and prospective buyers
PwC includes vendor due diligence and vendor assistance within its transaction advisory services, supporting companies that are selling a business or separating part of their operations. The work focuses on preparing financial information for potential purchasers, helping sellers address key issues before buyer due diligence begins and supporting a more structured transaction process.
Vendor assistance is available for transactions where support is required throughout the disposal process without issuing a full vendor due diligence report. The firm's specialists work alongside management and lead advisers, assisting with financial analysis, transaction planning and the identification of issues that could influence negotiations or the overall timetable.
Key Highlights
Vendor due diligence within transactions advisory
Supports business sales and carve-outs
Offers vendor due diligence and vendor assistance
Helps identify issues before buyer review
Works alongside management teams and advisers
Experience across domestic and international transactions
Services
Vendor due diligence
Vendor assistance
Transactions advisory
Financial due diligence
Business disposals
Carve-out support
Transaction planning
Financial analysis
Contact Information
Website: www.pwc.co.uk
Facebook: www.facebook.com/PwCUK
LinkedIn: www.linkedin.com/company/pwc-uk
Instagram: www.instagram.com/pwc_uk
Address: 1 Embankment Place, London, WC2N 6RH, United Kingdom
Phone: +44 (0)20 7583 5000
Henderson Loggie
Henderson Loggie includes vendor due diligence and vendor assistance within its corporate finance services for businesses planning a sale. Both services focus on preparing a company before it enters the market, although they follow different approaches. Vendor due diligence results in an independent report for potential buyers, while vendor assistance is centred on helping the seller resolve issues before the transaction moves forward.
The firm adapts the engagement to the circumstances of each business. Vendor assist is often used where owners want guidance through the preparation stage, while vendor due diligence can suit structured sales involving multiple bidders. Beyond reviewing financial information, the process may cover operational, tax and compliance matters that could influence buyer discussions later in the transaction.
Moore Kingston Smith offers vendor due diligence as part of its wider transaction services, supporting businesses involved in acquisitions, investments and disposals. The firm's due diligence team helps sellers review key financial information before buyer enquiries begin, giving management a clearer understanding of potential risks and areas that may require further explanation during negotiations.
Its transaction specialists advise businesses throughout the deal process, from the early planning stages through to completion. Depending on the transaction, support can include vendor assist, tax, IT and ESG due diligence alongside financial analysis. The firm works with a range of buyers, investors and private businesses, with a particular focus on the mid-market.
BDO has experience delivering vendor due diligence as part of its transaction services for businesses preparing for acquisitions or disposals. Vendor due diligence is used to review financial information before a transaction progresses, helping sellers present consistent information to prospective buyers and supporting a more structured sale process.
The firm's transaction specialists advise businesses across different industries, with vendor due diligence forming part of a wider deals practice that covers financial and tax aspects of corporate transactions. Depending on the engagement, the review can support management during negotiations and reduce the amount of additional financial investigation required later in the process.
Kreston Reeves offers vendor due diligence as part of its corporate finance services, helping sellers prepare financial and operational information before a transaction begins. The review is designed to give buyers and investors a clearer understanding of the business while allowing vendors to identify key risks before entering detailed negotiations.
Its due diligence team supports a range of transaction types, including business sales, acquisitions, investments and lending arrangements. Financial reviews can be combined with tax input, business valuations and wider corporate finance advice, with the scope adjusted to match the objectives of each transaction.
Key Highlights
Vendor due diligence within corporate finance
Supports buyers, sellers and investors
Reviews financial and operational information
Tax specialists available for due diligence
Flexible scope based on each transaction
Access to international advisory network
Services
Vendor due diligence
Financial due diligence
Pre-acquisition due diligence
Pre-investment due diligence
Pre-lend due diligence
Business valuations
Corporate tax advisory
Corporate finance advisory
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)330 124 1399
Price Bailey
Price Bailey approaches vendor due diligence as a way of helping sellers organise a controlled transaction process before approaching potential buyers. The firm distinguishes between vendor assistance and vendor due diligence, with each service designed for different stages of a business sale. Both aim to improve the quality of financial information available during negotiations and reduce unexpected issues later in the process.
Drawing on experience from both buy-side and sell-side transactions, the corporate finance team supports management with financial analysis, transaction planning and preparation for buyer enquiries. Vendor due diligence reports are produced from an independent perspective for potential purchasers, while vendor assistance helps businesses prepare information before formal due diligence begins.
Address: Anglia House, 6 Central Avenue, St Andrews Business Park, Thorpe St Andrew, Norwich, Norfolk, NR7 0HR
Phone: 01603 709330
PKF Smith Cooper
PKF Smith Cooper provides vendor due diligence for businesses planning a full or partial sale. The process is focused on preparing an independent report that can be shared with prospective acquirers, helping sellers present consistent financial information while supporting an organised sale process.
As an alternative, businesses can choose vendor assistance where a different level of support is more suitable for the transaction. The firm's transaction advisory team is involved throughout the preparation stage, helping management deal with financial matters before buyer due diligence begins and reducing the need for repeated information requests during negotiations.
Deloitte includes vendor due diligence within its mergers and acquisitions services, supporting businesses involved in corporate transactions across different sectors. Vendor due diligence forms part of a broader transaction offering that examines financial information before a sale, helping buyers and sellers understand key risks and areas requiring further review.
The firm's transaction specialists combine financial due diligence with commercial, operational and technology-related assessments where required. Businesses can access support across the full transaction lifecycle, from early planning through to completion, with the scope shaped around the size and complexity of each deal.
Key Highlights
Vendor due diligence within M&A services
Supports corporate and private equity transactions
Part of end-to-end transaction support
Financial, commercial and IT due diligence
Covers different stages of the deal process
Experience across domestic and international transactions
Services
Vendor due diligence
Acquisition due diligence
Commercial due diligence
IT due diligence
M&A advisory
Transaction support
Financial due diligence
Strategy and transactions
Contact Information
Website: www.deloitte.com
Facebook: www.facebook.com/deloitteuk
Twitter: x.com/deloitteuk
LinkedIn: www.linkedin.com/company/deloitte
Address: 1 New Street Square, London, EC4A 3HQ, United Kingdom
Phone: +44 (0)20 7936 3000
Final Thoughts
The right vendor due diligence provider depends on the size of the transaction, the complexity of the business and the level of support needed throughout the sale process. Some organisations look for a firm that can prepare an independent vendor due diligence report for potential buyers, while others prefer vendor assistance to help them identify and resolve issues before going to market.
Experience with similar transactions, access to tax and specialist advisers, and the ability to communicate findings clearly are all factors that can influence the decision. It is also worth considering whether the firm can provide wider transaction support if additional advice is needed as the sale progresses.
This guide highlights a range of UK firms offering vendor due diligence services. Each has a different approach, so comparing their experience, service offering and transaction expertise can help businesses choose the provider that best fits their objectives.
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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An internal audit function must be assessed by a qualified, independent assessor at least once every five years. That requirement is Standard 8.4 of the Global Internal Audit Standards, which…
An internal audit function must be assessed by a qualified, independent assessor at least once every five years. That requirement is Standard 8.4 of the Global Internal Audit Standards, which…
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