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Transaction Advisory Firms in the UK: Companies and Services Guide (2026)

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Acumon Chartered Accountants ·13 min read

UK transaction advisory firms vary considerably in scale, deal focus and the type of support they provide. Some concentrate on owner-managed and mid-market transactions, while others have multidisciplinary teams covering large and cross-border deals. This guide provides a practical overview rather than ranking the firms.

Acumon logo

Acumon

Acumon is a UK firm of chartered accountants providing specialist advisory and transaction support services to businesses involved in acquisitions, disposals, restructuring, and ownership transitions.

The firm works with organisations ranging from owner-managed businesses and growing companies through to larger corporate groups and international structures. Transaction engagements are delivered on a partner-led basis with clearly scoped, fixed fees agreed up front and a named expert as the day-to-day contact.

Acumon’s advisory services cover the full transaction lifecycle. This includes support for buying a business (target identification, valuation, negotiation, funding advice, and post-acquisition integration), selling a business (exit planning, vendor due diligence, valuation, tax optimisation, and negotiation support), and management buy-outs and buy-ins (tax optimisation, funding structures, due diligence, contract negotiation, and management incentive plans).

The firm provides buy-side and vendor financial due diligence, commercial due diligence, tax due diligence, and independent business valuations (indicative and formal) for acquisitions, disposals, tax planning, and disputes. Additional capabilities include tax-efficient company demergers and group restructurings (with HMRC clearances where appropriate), succession planning (including employee ownership trusts), and financial modelling for planning, fundraising, M&A, and strategic decision-making.

Acumon’s experience includes direct involvement as an acquirer in multiple successful acquisitions. Partner-level expertise draws on real-world transaction background, including private equity and major infrastructure advisory work. The firm integrates transaction advice with its broader capabilities in tax, accounting, and audit to support clients before, during, and after deals.

Transaction Advisory Capabilities:

Acumon provides specialist advisory services across a wide range of transaction types and organisational structures.

These include:

  • Buy-side acquisition support and business purchase advice
  • Sell-side transaction advisory and business sale support
  • Financial due diligence (buy-side and vendor)
  • Commercial due diligence
  • Tax due diligence
  • Vendor due diligence
  • Business valuations (indicative and formal)
  • Succession planning, including employee ownership trusts
  • Tax-efficient demergers and group restructurings
  • Financial modelling for M&A, fundraising, and strategic decisions

These services enable the firm to support organisations through the complete transaction lifecycle, from early planning through to completion and beyond.

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 provide audit services to groups that include entities in both the UK and key international financial centres.

Core Services:

In addition to statutory external audit, Acumon provides a range of services that support financial reporting and governance.

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

Audit work is often delivered alongside discussions with management and boards regarding financial reporting processes and governance frameworks.

Many organisations initially encounter statutory audit requirements as they grow and exceed the audit exemption thresholds set out in the Companies Act.

Acumon works with businesses that are:

  • Approaching their first statutory audit
  • Preparing for external investment
  • Expanding into international markets
  • Operating within corporate group structures

Early engagement with an audit firm can help ensure that financial reporting systems and documentation are aligned with statutory audit requirements.

Contact Information:

Grant Thornton UK logo

Grant Thornton UK

Grant Thornton has a dedicated Transaction Advisory Services practice supporting acquisitions, disposals, refinancing and capital raising. Its offering spans financial due diligence, vendor due diligence, vendor assist, bid support, financial modelling, transaction tax, SPA advice and reporting accountant services.

The practice has a clear mid-market orientation, with a national team of nearly 200 advisers. Financial due diligence work covers areas such as underlying earnings, KPIs, working capital and net debt, while the wider deals practice can also draw on corporate finance, valuations and operational deal specialists.

Key Facts:

  • Ideal for: Mid-market corporates, investors and private equity-backed transactions
  • Core services: Financial and vendor due diligence, transaction tax, SPA advisory, modelling, vendor assist and bid support
  • Coverage: National UK transaction advisory team
  • Notable strength: Broad due diligence and deal support within one advisory practice

Contact Information:

  • Website: www.grantthornton.co.uk
  • LinkedIn: www.linkedin.com/company/grant-thornton-uk
  • Instagram: www.instagram.com/gt_trainees
  • Address: Level 8, 120 Bothwell St, Glasgow G2 7JS  
  • Phone: +44 (0)141 223 0000
KPMG UK logo

KPMG UK

KPMG’s Transaction Services practice sits within its wider Deal Advisory operation. The team works across the M&A lifecycle, from early evaluation through deal execution and post-deal integration or separation. It supports acquisitions, disposals, joint ventures, buy-outs and IPO-related transactions.

Around 450 transaction services professionals form part of the UK practice. Alongside financial due diligence, KPMG offers sell-side advisory, SPA support, cash and working capital analysis, ESG due diligence, valuations, corporate finance and debt advisory.

Key Facts:

  • Ideal for: Corporates, financial investors and businesses handling complex or cross-border transactions
  • Core services: Transaction services, due diligence, SPA advisory, valuations, corporate finance and M&A support
  • Team: Around 450 UK transaction services professionals
  • UK presence: Offices across major UK business centres, including London, Manchester, Birmingham, Leeds and Edinburgh

Contact Information:

  • Website: kpmg.com
  • Facebook: www.facebook.com/KPMG
  • Twitter: x.com/kpmguk
  • LinkedIn: www.linkedin.com/company/kpmg-uk
  • Address: 319 St Vincent Street, G2 5AS , Glasgow, UK  
  • Phone: +44 (0) 141 226 5511
S&W logo

S&W

S&W provides transaction services to entrepreneurs, corporates and private equity clients, with a particular focus on the mid-market. Its team handles acquisitions and disposals from initial preparation through to post-deal support.

The firm’s transaction offering includes financial due diligence, vendor due diligence, SPA advice, M&A tax due diligence and value creation work. Operational, technology and cyber considerations can also be brought into transaction reviews where needed. 

Key Facts:

  • Ideal for: Mid-market businesses, entrepreneurs, private equity firms and acquisitive corporates
  • Core services: Financial and vendor due diligence, SPA advisory, M&A tax and value creation
  • Specialization: Mid-market transactions with partner involvement
  • International capability: Cross-border M&A support through Oaklins and CLA Global relationships

Contact Information:

  • Website: www.swgroup.com
  • Twitter: x.com/S_W_Group
  • LinkedIn: www.linkedin.com/company/swgroupuk
  • Address: 3rd floor, 56 Wellington Street, Leeds LS1 2EE 
  • Phone: +44 113 398 1100
BDO UK logo

BDO UK

BDO combines transaction services with a broader Deal Advisory practice that covers the transaction from M&A strategy and planning through due diligence and post-deal value creation. The Transaction Services team works with corporate buyers and sellers, financial investors, private equity funds and banking institutions.

Its due diligence capabilities extend beyond financial analysis to commercial, ESG, IT, operational and tax reviews. BDO also provides SPA advice, valuations, transaction structuring, modelling and integration support, giving clients the option to bring several deal workstreams under one advisory group.

Key Facts:

  • Ideal for: Mid-market transactions, private equity and corporate M&A
  • Core services: Financial, commercial, tax, ESG, operational and IT due diligence, plus SPA and valuation work
  • UK presence: Deal Advisory services available through BDO’s UK office network
  • Notable strength: Multidisciplinary due diligence across financial and non-financial deal risks

Contact Information:

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

PwC UK

PwC’s Transaction Services practice combines financial, commercial and operational expertise for acquisitions, disposals, strategic alliances, refinancing and capital raising. The team works on both buyer and vendor assignments and supports transactions across sectors including financial services, healthcare, technology, industrials, consumer markets and real estate.

Services include financial and vendor due diligence, M&A due diligence, ESG due diligence, commercial due diligence, SPA support and asset sales. Buyers can also use PwC for analysis covering maintainable earnings, cash flow, market assumptions, synergies and deal structuring.

Key Facts:

  • Ideal for: Corporate and financial buyers, sellers and larger multidisciplinary transactions
  • Core services: Financial, vendor, commercial, operational and ESG due diligence, SPA support and deal advice
  • Sector coverage: Financial services, healthcare, TMT, consumer, industrials, infrastructure and real estate
  • Notable strength: Integration of transaction services with wider corporate finance and strategy capabilities

Contact Information:

  • Website: www.pwc.com
  • Facebook: www.facebook.com/PwCUK
  • LinkedIn: www.linkedin.com/company/pwc-uk
  • Instagram: www.instagram.com/pwc_uk
  • Address: 2 Glass Wharf, Bristol BS2 0FR 
  • Phone: +44 (0)117 955 7779
Menzies logo

Menzies

Menzies combines transaction services and financial due diligence within its Deal Advisory practice. The firm typically advises on transactions with enterprise values between £3 million and £75 million, working with privately owned and family businesses, owner-managed companies and multinational organisations.

Its transaction advisory work includes buy-side and sell-side support, financial due diligence, vendor due diligence, transaction structuring, SPA advice, business valuations, fundraising and succession planning. The firm can also coordinate cross-border financial due diligence through the HLB International network.

Key Facts:

  • Ideal for: Privately owned businesses, owner-managed companies and mid-market transactions
  • Typical deal range: £3 million to £75 million
  • Core services: Financial due diligence, vendor support, valuations, SPA advice, fundraising and M&A advisory
  • International capability: Cross-border support through HLB International

Contact Information:

  • Website: www.menzies.co.uk
  • E-mail: [email protected]
  • LinkedIn: www.linkedin.com/company/menzies-llp
  • Instagram: www.instagram.com/menzies_llp
  • Address: One Express, 1 George Leigh Street, Manchester M4 5DL 
  • Phone: +44 (0)333 091 0411
EY logo

EY

EY brings together transaction and corporate finance capabilities for M&A, divestments and other strategic transactions. Its teams work with executives, corporates and private equity investors from initial strategy and diligence through valuation, execution, integration or separation.

Due diligence can cover financial, tax, commercial, operational, IT, HR, cybersecurity, sustainability and other areas. EY’s wider transaction offering also includes M&A advisory, transaction tax, valuations, business modelling, divestment strategy and integration consulting.

Key Facts:

  • Ideal for: Corporates, boards, private equity firms and complex multidisciplinary transactions
  • Core services: Due diligence, M&A advisory, corporate finance, valuations, modelling, integration and separation
  • Due diligence scope: Financial, commercial, tax, operational, technology, cyber, HR and sustainability reviews
  • Notable strength: Combination of strategic transaction analysis and execution support

Contact Information:

  • Website: www.ey.com
  • Facebook: www.facebook.com/EY
  • Twitter: x.com/EYnews
  • LinkedIn: www.linkedin.com/company/ernstandyoung
  • Address: The Paragon, Counterslip, Bristol, BS1 6BX
  • Phone: +44 117 981 2050
Forvis Mazars logo

Forvis Mazars

Forvis Mazars provides transaction services within its UK Deals and Financial Advisory practices. Its teams advise on acquisitions, disposals and reorganisations in the UK and internationally, including both acquisition and vendor-side due diligence.

Acquisition work can cover financial and tax risks, underlying performance, working capital, net debt, forecast assumptions and financial elements of acquisition agreements. On the sell-side, Forvis Mazars offers vendor due diligence and vendor assistance, while post-completion services include price adjustment analysis and support around completion mechanisms.

Key Facts:

  • Ideal for: Corporates, private equity investors and businesses with domestic or cross-border deals
  • Core services: Acquisition due diligence, vendor due diligence, SPA support, financial diagnostics and post-deal support
  • International capability: Dedicated transaction services teams across 38 countries
  • Specialization: Financial and tax analysis around acquisition and disposal processes

Contact Information:

  • Website: www.forvismazars.com
  • Twitter: x.com/ForvisMazarsUK
  • LinkedIn: www.linkedin.com/company/forvis-mazars-in-the-uk
  • Instagram: www.instagram.com/forvismazarsuk
  • Address: 100 Queen Street, Glasgow, G1 3DN, United Kingdom 
  • Phone: +44 141 227 2400
Deloitte UK logo

Deloitte UK

Deloitte provides Transaction Services alongside its wider M&A Advisory and Corporate Finance capabilities. Its transaction team works with private equity, infrastructure and real estate funds, as well as private and public companies throughout the deal lifecycle.

Financial due diligence covers acquisition and vendor assignments, while additional capabilities include commercial and IT due diligence, M&A operations, ESG, equity capital markets and integration or separation work. Deloitte’s M&A Advisory practice can also manage transactions from strategic consideration through execution and post-deal support.

Key Facts:

  • Ideal for: Larger corporates, investment funds, private equity and complex transactions
  • Core services: Financial, commercial and IT due diligence, M&A advisory, operations, ESG and capital markets support
  • Transaction coverage: Acquisitions, disposals, divestitures and other M&A situations
  • Notable strength: Broad functional support before, during and after a transaction

Contact Information:

  • Website: www.deloitte.com
  • Facebook: www.facebook.com/deloitteuk
  • Twitter: x.com/deloitteuk
  • LinkedIn: www.linkedin.com/company/deloitte
  • Address: 100 Embankment, Cathedral Approach, Manchester, M3 7FB, United Kingdom  
  • Phone: +44 (0)161 829 3800
FRP Advisory logo

FRP Advisory

FRP Advisory’s Financial Advisory division includes a dedicated Transaction Services practice supporting buyers and sellers. The team prepares independent financial analysis aimed at clarifying key deal issues, risks and the assumptions behind an investment decision.

Services include buy-side financial due diligence, vendor due diligence and vendor assistance, with support continuing into negotiations and post-transaction analysis where needed. FRP also has adjacent financial modelling, valuations, lender services, corporate finance and M&A capabilities that can be brought into a transaction.

Key Facts:

  • Ideal for: Private equity firms, corporates, lenders and mid-market buyers and sellers
  • Core services: Buy-side due diligence, vendor due diligence, vendor assistance and post-transaction analysis
  • Related capabilities: Financial modelling, valuations, lender services and M&A advisory
  • UK presence: Transaction specialists operate from locations including London, Reading, Bristol and Norwich

Contact Information:

  • Website: www.frpadvisory.com
  • E-mail: [email protected]
  • Address: 110 Cannon Street, London EC4N 6EU 
  • Phone: +44 (0)20 3005 4000
Moore Kingston Smith logo

Moore Kingston Smith

Moore Kingston Smith provides transaction services for buyers, investors, sellers and companies raising capital. Its team combines financial analysis with commercial and operational understanding and has a particular focus on mid-market transactions.

The firm handles due diligence from heads of terms through post-completion, supporting trade buyers, listed companies, private equity firms, family offices and venture capital investors. Sector experience includes media and technology, education, business services, manufacturing and distribution, with international support available through the Moore Global network.

Key Facts:

  • Ideal for: Mid-market buyers, investors and private company transactions
  • Core services: Transaction due diligence, reporting accountant services and wider corporate finance support
  • Sector focus: Media and technology, education, business services, manufacturing and distribution
  • International capability: Cross-border support through Moore Global

Contact Information:

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

Saffery

Saffery operates a national Transaction Services team supporting acquisitions, disposals, debt raising and exit preparation. The practice primarily works with SMEs and owner-managed businesses, while also supporting private equity, corporate clients and transactions involving international parties with UK interests.

Its services include financial due diligence, tax due diligence, vendor due diligence, vendor assistance, bid support and reporting accountant assignments. The team handles both buy-side and sell-side work and has experience with areas such as working capital, locked-box mechanisms, completion accounts and SPA advisory.

Key Facts:

  • Ideal for: SMEs, owner-managed companies, private equity and mid-market deals
  • Core services: Financial and tax due diligence, vendor due diligence, vendor assist, bid support and reporting accountant services
  • Coverage: National UK Transaction Services team
  • Transaction experience: Buy-side, sell-side and cross-border transaction support

Contact Information:

  • Website: www.saffery.com
  • E-mail: [email protected]
  • LinkedIn: www.linkedin.com/company/saffery
  • Instagram: www.instagram.com/saffery_uk
  • Address: 10 Wellington Place, Leeds, LS1 4AP 
  • Phone: +44 (0)113 887 5538
RSM UK logo

RSM UK

RSM’s Deal Services practice supports entrepreneurs, corporates and private equity investors through business sales, acquisitions, carve-outs, fundraising and related transactions. Its transaction services specialists have a strong middle-market orientation and can work from pre-deal preparation through post-completion integration.

Due diligence teams combine financial analysis and data analytics to examine value drivers and transaction risks. RSM can also provide tax structuring, SPA advisory, valuations, accounting advice and post-deal support, with UK and international specialists brought together when a transaction crosses jurisdictions.

Key Facts:

  • Ideal for: Mid-market corporates, private equity and acquisitive businesses
  • Core services: Financial due diligence, transaction tax, SPA advisory, valuations and post-deal support
  • Transaction types: Acquisitions, disposals, carve-outs, fundraising and refinancing-related work
  • Notable strength: Dedicated national Transaction Services leadership and multidisciplinary deal teams

Contact Information:

  • Website: www.rsmuk.com
  • LinkedIn: www.linkedin.com/company/rsm-uk
  • Instagram: www.instagram.com/rsm.uk
  • Address: 5th Floor, Central Square, 29 Wellington Street, Leeds, LS1 4DL 
  • Phone: +44 (0)113 285 5000
PKF Smith Cooper logo

PKF Smith Cooper

PKF Smith Cooper’s Transaction and Advisory Services team works with businesses buying or selling companies and with lenders involved in transaction and refinancing processes. The firm has a clear Midlands presence and works with the wider PKF network for assignments requiring international support.

Financial due diligence and tax due diligence form the core of the service. The team also provides vendor due diligence, bank and refinancing reviews, vendor assistance, business valuation advice and guidance around deal mechanisms. Engagements are senior-led, with the advisory team staying involved throughout the project rather than limiting its role to preparation of a report.

Key Facts:

  • Ideal for: Mid-market businesses, buyers, sellers and lenders
  • Core services: Financial and tax due diligence, vendor due diligence, refinancing reviews and vendor assist
  • Location: Offices across the Midlands, including Derby, Nottingham, Birmingham and Telford
  • International capability: Member of the global PKF network

Contact Information:

  • Website: www.pkfsmithcooper.com
  • Facebook: www.facebook.com/PKFsmithcooper
  • LinkedIn: www.linkedin.com/company/pkfsmithcooper
  • Instagram: www.instagram.com/pkfsmithcooper
  • Address: Cornerblock, 2 Cornwall St, Birmingham B3 2DX, United Kingdom
  • Phone: 03333446306 

Conclusion

Transaction advisory services in the UK range from focused mid-market practices to large multidisciplinary teams capable of coordinating complex international deals. The differences are most noticeable in typical transaction size, the level of senior involvement and how far each firm goes beyond financial due diligence into commercial, operational, tax, technology, valuation and post-deal work.

For owner-managed and mid-market transactions, firms with partner-led teams and flexible due diligence scopes may be a practical fit. Larger or more complex deals can require deeper sector resources and specialists across several jurisdictions. There is no single provider that suits every transaction, so the right choice depends on deal size, required diligence areas, geographic scope, budget and the support needed before and after completion.

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