Practical Guide to Accountancy Services Companies in London

London is still one of the world’s major financial hubs, where businesses of every size rely on solid accountancy support for accounts preparation, tax compliance, payroll processing, audit and risk management. This is a neutral overview of noticeable companies active in the London market right now – not a ranked list or top picks, just a snapshot to give you useful context.

The range covers huge international networks that handle full-scope services for listed companies and multinationals, mid-tier firms with strong audit and advisory for mid-market entities, and specialists in forensic, restructuring or targeted risk work. The right choice always depends on your company size, industry, compliance requirements, whether you need day-to-day bookkeeping/payroll or strategic risk/tax planning. The goal here is to help you compare what each offers so you can identify a partner that fits your situation.

Acumon

Acumon is a chartered accountancy and advisory firm based in West London, with its main office in Ealing. Originally rooted in a respected local practice, it has grown into a leading UK firm with UK-based professionals, serving clients throughout the country – including Jersey and the Isle of Man – as well as international subsidiaries of UK groups.

The firm delivers a complete range of tailored services, from on-demand bookkeeping and statutory accounts preparation to management reporting, VAT compliance, and specialist financial statements. It also handles full tax advisory and compliance (covering corporation tax, personal tax, R&D credits, EIS/SEIS, property taxes, and HMRC enquiries), external audits, payroll processing (including PAYE, CIS, and pensions), and broader business support. Acumon works with a wide variety of clients, including startups, established companies, charities, not-for-profits, co-operatives, mutuals, and flat management companies, always focusing on practical, high-quality solutions delivered by experienced UK professionals.

Key Highlights:

• All professionals UK-based
• ICAEW-registered audit firm
• Serves UK PLCs, charities and international subsidiaries
• HMRC-experienced staff in tax services
• Dedicated accounts and bookkeeping on-demand
• Comprehensive tax planning with multiple areas
• External audit for regulated entities

Services:

• Accountancy services in London
• Accounts and bookkeeping services
• Tax advisory and compliance
• External audit services
• Payroll processing and administration
• Business support and advisory
• Management accounts and financial planning

Contact Information:

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

PwC

PwC provides audit services that centre on financial reporting quality and stakeholder trust. The approach involves understanding the business, analysing data flows and controls, using technology for testing and iterative risk assessment to form independent opinions. Tools support large-scale data analysis and focus on material risks, with emphasis on professional scepticism and transparency in complex settings. PwC also offers tax services (compliance, advisory, indirect taxes, employment tax and payroll), finance managed services (including outsourced accounting and bookkeeping elements for mid-sized businesses), and broader HR/payroll support.

Key Highlights:

• Technology and data analytics in audits
• Iterative risk assessment throughout engagements
• Independence and professional scepticism
• Capital markets and reporting support
• Tax compliance and advisory options
• Payroll and employment tax services

Services:

• Audit
• Non-financial assurance
• Capital markets assurance
• Tax advisory and compliance
• Payroll and employment tax
• Finance managed services (accounting support)

Contact Information:

• Website: www.pwc.co.uk
• Phone: +44 (0)20 7583 5000
• 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

Deloitte

Deloitte delivers assurance on financial and non-financial information, drawing on accounting expertise and technology. Work includes reporting trends, internal controls, sustainability standards and emerging areas like AI assurance. The approach helps finance teams meet regulatory requirements and strengthen controls. Deloitte also provides tax compliance, advisory and implementation, payroll and workforce management (including global payroll operate, consulting, and HR/payroll delivery), plus mobility and immigration support.

Key Highlights:

• Technology integration in assurance
• Coverage of financial and non-financial controls
• Sustainability and emerging standards focus
• Tax compliance and advisory
• Payroll and workforce management

Services:

• Accounting and reporting assurance
• Controls assurance
• Sustainability and emerging assurance
• Tax advisory and compliance
• Payroll and workforce management

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
• Instagram: www.instagram.com/deloitte_uk 

EY

EY offers assurance services to build trust in business and capital markets through independent audit, technology risk work and analytics-driven reviews. Additional areas cover sustainability, climate change, data risks and complex reporting standards. The focus supports reputation protection, decision-making and finance function efficiency. EY provides tax services (compliance, advisory, international tax), forensic and integrity services, and broader advisory, though payroll/bookkeeping are not core or prominently listed in assurance.

Key Highlights:

• Analytics-driven independent audits
• Technology and sustainability risk coverage
• Support for complex reporting standards
• Forensic and integrity services
• Tax advisory elements

Services:

• Audit
• Technology risk
• Sustainability assurance and ESG reporting
• Financial accounting advisory
• Forensic and integrity services
• Tax advisory

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/pages/Ernst-Young/195665063800329
• Twitter: x.com/EYnews

KPMG

KPMG conducts independent audits with a focus on integrity, professional scepticism and technology to improve transparency. Services include accounting advisory, broader assurance and ESG reporting support. The smart audit platform helps identify critical issues in financial and non-financial information. KPMG also offers tax services (compliance, advisory, indirect taxes), payroll and workforce solutions in some managed services contexts, though not always highlighted in audit sections.

Key Highlights:

• Technology-enhanced audit transparency
• Independent audit focus
• ESG reporting support
• Accounting advisory
• Tax compliance options

Services:

• Audit
• Accounting advisory
• ESG reporting
• Assurance
• Tax advisory and compliance
• Payroll and workforce elements (in managed services)

Contact Information:

• Website: kpmg.com
• Phone: +44 (0)20 7311 1000
• Address: 15 Canada Square, Canary Wharf, London, E14 5GL
• Facebook: www.facebook.com/KPMG
• LinkedIn: www.linkedin.com/company/kpmg-uk
• Twitter: x.com/kpmguk

BDO UK

BDO UK provides forensic accounting services for fraud, financial crime and commercial disputes. The practice includes investigations into suspected wrongdoing, asset tracing and recovery, expert witness support in courts or tribunals, plus quantification of losses across sectors. Forensic technology supports electronic data capture, review and disclosure with AI-assisted tools. Prevention measures cover tailored fraud and corruption strategies. BDO also offers UK payroll services (processing, PAYE, auto-enrolment pensions, P11D, global payroll elements), employment tax compliance and advisory, plus broader audit, tax and outsourcing including some accounting support.

Key Highlights:

• Fraud and financial crime investigations
• Commercial dispute quantification
• Expert witness testimony
• Forensic technology with AI tools
• Fraud prevention strategies
• Asset tracing and recovery
• Regulatory breach support

Services:

• Forensic investigations
• Dispute advisory
• Expert witness support
• Fraud prevention advisory
• Asset recovery
• UK payroll services
• Employment tax compliance

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 UK

Grant Thornton UK delivers forensic and investigation services for fraud, integrity issues and disputes. Work covers uncovering facts in special situations, litigation support, contentious valuations and forensic data analytics for complex information. Whistleblowing frameworks manage risks confidentially, while corporate intelligence handles cross-border matters. The approach includes investigative and advisory roles with expert witness capacity. Grant Thornton also provides payroll solutions (as part of employer solutions), employment tax reporting/compliance, accounting services (bookkeeping, management accounts, VAT/corporate tax compliance), and broader tax advisory.

Key Highlights:

• Fraud and special situations investigations
• Litigation and disputes advisory
• Forensic data analytics
• Whistleblowing and risk management
• Corporate intelligence
• Payroll and employment tax solutions
• Bookkeeping and compliance support

Services:

• Forensic investigations
• Disputes advisory
• Whistleblowing support
• Corporate intelligence
• Forensic data analytics
• Payroll solutions
• Accounting services (bookkeeping/management accounts)

Contact Information:

• Website: www.grantthornton.co.uk
• Phone: +44 (0)20 7383 5100
• Email: malcolm.a.gomersall@uk.gt.com
• Address: 8 Finsbury Circus, London, EC2M 7EA
• LinkedIn: www.linkedin.com/company/grant-thornton-uk
• Instagram: www.instagram.com/gt_trainees

RSM UK

RSM UK provides audit services with a risk-based focus and innovative technology for efficiency. Statutory audits target high-risk financial statement areas, while internal audit and controls identify and mitigate strategic, financial and operational risks. Quality assurance comes through monitoring, policies and technical guidance. The method offers insights beyond basic compliance. RSM also includes tax, advisory and outsourcing elements in broader services, though payroll/bookkeeping are not core in audit sections.

Key Highlights:

• Risk-based approach to audits
• Technology integration for efficiency
• Internal audit and controls coverage
• Strategic and operational risk mitigation
• Quality assurance framework
• Insights beyond compliance

Services:

• Statutory audit
• Internal audit and controls
• Risk assurance
• Audit technology support
• Compliance and advisory elements

Contact Information:

• Website: www.rsmuk.com
• Phone: +44 (0)20 3201 8000
• Email: info@rsmuk.com
• Address: 25 Farringdon Street, London, EC4A 4AB
• LinkedIn: www.linkedin.com/company/rsm-uk
• Instagram: www.instagram.com/rsm.uk

FRP Advisory

FRP Advisory provides forensic accounting and financial advisory services, often in restructuring and distress situations. Work includes forensic investigations, asset tracing, loss quantification and dispute resolution to maximise recoveries through accounting expertise. The approach assesses financial situations, provides strategic planning and hands-on stabilisation. Risk management supports resilience and long-term value. Focus is on bespoke solutions using forensic accounting in insolvency and distress scenarios.

Key Highlights:

• Forensic accounting and investigations
• Asset tracing and recovery
• Expert witness and dispute support
• Forensic advisory in restructuring cases
• Risk management in distress situations

Services:

• Forensic investigations
• Dispute advisory
• Expert witness support
• Asset tracing
• Forensic advisory elements
• Restructuring advisory with forensic accounting support

Contact Information:

• Website: www.frpadvisory.com
• Phone: +44 (0)20 3005 4000
• Email: contactus@frpadvisory.com
• Address: 110 Cannon Street, London, EC4N 6EU

Menzies LLP

Menzies LLP handles audit and assurance for corporate entities, not-for-profits, pension schemes and grant-funded bodies. The process starts with business understanding to tailor work and minimise disruption. Emphasis is on identifying key risks, clear communication and practical recommendations. Partner involvement ensures transparent delivery. Assurance reviews add insight where needed. Menzies also provides tax and advisory services in broader offerings.

Key Highlights:

• Corporate and not-for-profit audits
• Pension scheme audit coverage
• Grant audit and assurance
• Key risk focus
• Minimal disruption approach
• Practical recommendations

Services:

• Corporate audit and assurance
• Not-for-profit audit and assurance
• Pension scheme audits
• Grant audit and assurance
• Assurance reviews
• Tax advisory elements

Contact Information:

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

PKF Littlejohn

PKF Littlejohn provides statutory audit and tailored assurance services to build trust and transparency. Statutory audits offer independent reviews for listed/private companies, owner-managed businesses, private equity-backed entities and multinational groups, with a focus on robust, efficient processes. Governance, risk and control assurance includes internal audit, IT assurance (with cyber security and data protection), internal controls, ESG assurance, compliance monitoring, outsourcing/co-sourcing and training. Institutional donor audits cover financial/systems audits, fraud investigations, performance audits and pre-grant due diligence. Broader services include tax and accountancy support in some contexts, though payroll/bookkeeping are not core in audit sections.

Key Highlights:

• Statutory audits for listed/private entities
• Governance and internal controls assurance
• IT assurance with cyber security
• ESG and compliance monitoring
• Fraud investigations in donor audits
• Risk minimisation focus
• Internal audit support

Services:

• Statutory audit
• Governance assurance
• Risk and control assurance
• IT assurance
• ESG assurance
• Internal audit support
• Compliance monitoring

Contact Information:

• Website: www.pkf-l.com
• Phone: +44 (0)20 7516 2200
• Email: info@pkf-l.com
• Address: 15 Westferry Circus, Canary Wharf, London E14 4HD
• LinkedIn: www.linkedin.com/company/littlejohn
• Twitter: x.com/PKF_Littlejohn
• Instagram: www.instagram.com/pkf.littlejohn

Forvis Mazars UK

Forvis Mazars UK focuses on audit and assurance with independence, rigour and a human-centric approach beyond compliance. The service provides constructive challenge, insight and transparency to build confidence in organisational reporting for stakeholders. It serves regional, national and international companies of all sizes/structures, combining skills, knowledge and consistent methodologies. Emphasis is on mutual trust, professional standards and sustainable value in regulated environments. Forvis Mazars also offers tax services (compliance/advisory), financial advisory and consulting in broader UK offerings, though payroll/bookkeeping are not highlighted in audit/assurance.

Key Highlights:

• Independent and rigorous audits
• Constructive challenge approach
• Focus on reporting transparency
• Builds stakeholder confidence
• Supports financial information trust
• Integrated skills and methodologies

Services:

• Audit and assurance
• Governance advisory elements
• Risk and control advisory
• Transparency and reporting advisory
• Tax advisory and compliance
• Financial advisory

Contact Information:

• Website: www.forvismazars.com
• Phone: +44 (0) 20 7063 4000
• Address: 30 Old Bailey, London, EC4M 7AU, United Kingdom
• LinkedIn: www.linkedin.com/company/forvis-mazars-in-the-uk
• Twitter: x.com/ForvisMazarsUK
• Instagram: www.instagram.com/forvismazarsuk

Crowe UK

Crowe UK delivers audit services with a focus on high-quality, responsive work that meets business needs. The process applies sector specialist knowledge for rigour, technical standards and constructive challenge. Statutory audit forms a core part of financial governance and reporting. Assurance provides comfort to owners, stakeholders and regulators. Financial reporting guidance covers UK standards like FRS. Crowe also offers broader advisory and tax services in some contexts, though payroll/bookkeeping are not prominent in audit.

Key Highlights:

• High-quality statutory audit focus
• Responsive to business needs
• Sector specialist knowledge applied
• Rigour and constructive challenge
• Assurance for stakeholder comfort
• Guidance on financial reporting standards

Services:

• Statutory audit
• Assurance services
• Financial reporting guidance
• Governance advisory elements
• Risk advisory elements
• Forensic advisory support

Contact Information:

• Website: www.crowe.com
• Phone: +44 (0)20 7842 7100
• Email: nick.jones@crowe.co.uk
• Address:  55 Ludgate Hill, London, EC4M 7JW
• LinkedIn: www.linkedin.com/company/crowe-uk
• Twitter: x.com/CroweUK
• Instagram: www.instagram.com/crowe_uk

Quantuma

Quantuma specialises in forensic accounting for investigations and disputes. The service covers fraud detection, asset tracing, loss quantification and expert witness support in legal/regulatory matters. Work often connects to restructuring or insolvency where financial evidence is key. Investigations analyse records/transactions for commercial disagreements, employee theft or compliance breaches. Independent forensic insight supports resolution in high-stakes issues.

Key Highlights:

• Fraud and financial crime investigations
• Asset tracing and recovery
• Expert witness in disputes
• Loss quantification support
• Links to restructuring cases
• Compliance and breach analysis

Services:

• Forensic investigations
• Dispute advisory
• Expert witness support
• Asset tracing
• Fraud detection
• Restructuring-linked forensic

Contact Information:

• Website: www.quantuma.com
• Phone: +44 (0)20 3856 6720
• Address: 20 St. Andrew Street, London, EC4A 3AG, United Kingdom
• LinkedIn: www.linkedin.com/company/quantuma
• Twitter: x.com/quantuma1

MHA

MHA provides audit and accounts services with a statutory focus for diverse entities. The work includes risk assessment, controls review and reporting under UK standards. Partner-led delivery offers insights alongside compliance. Corporate finance ties in for growth/transaction support. Advisory covers governance or operational clarity. Mid-sized businesses often use this for reliable audits plus strategic input.

Key Highlights:

• Statutory audit for diverse entities
• Risk and controls assessment
• Partner-led transparent delivery
• Insights beyond basic compliance
• Ties to corporate finance
• Governance advisory elements

Services:

• Statutory audit
• Accounts services
• Corporate finance advisory
• Governance advisory elements
• Risk management advisory
• Transaction support advisory

Contact Information:

• Website: www.mha.co.uk
• Phone: +44 (0)20 7429 4100
• Email: webenquiries@mha.co.uk
• Address: 2 London Wall Place, London, EC2Y 5AU
• LinkedIn: www.linkedin.com/company/mha-uk
• Facebook: www.facebook.com/people/MHA-Accountants/100063452388108
• Instagram:  www.instagram.com/mhaaccountants

Saffery

Saffery offers audit and assurance services with partner involvement for various entities. The approach includes statutory audits, risk focus and compliance in regulated environments. Advisory elements tie in for governance or operational clarity. It aims for straightforward delivery to build reporting trust. Saffery also provides tax advisory in broader services.

Key Highlights:

• Statutory audit coverage
• Partner-led approach
• Focus on compliance needs
• Some advisory integration
• Suited to varied entities
• Governance advisory elements

Services:

• Audit and assurance
• Governance advisory elements
• Risk management advisory
• Forensic advisory elements
• Tax advisory

Contact Information:

• Website: www.saffery.com
• Phone: +44 (0)20 7841 4000
• Email: info@saffery.com
• Address: 71 Queen Victoria Street, London EC4V 4BE, UK
• LinkedIn: www.linkedin.com/company/saffery
• Instagram: www.instagram.com/saffery_uk

Conclusion

Choice depends on your organisation’s scale, sector, maturity of processes and specific regulatory or operational needs. Some companies deliver broad integrated services covering accounts, tax, payroll and audit; others focus on specialised areas like forensic investigations, internal controls or restructuring support. This guide gives neutral context for comparison and finding a suitable partner. The right partner delivers independent assurance and practical steps to reduce risks and support resilience.