Top 20 Tax Consulting Firms: Comprehensive Advisory for Global Tax Strategy and Compliance

1. Deloitte

• Founders: William Watt Deloitte (origin)
• Founded Year: 1845
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax consulting & compliance, international tax strategy, transfer‑pricing, M&A tax advisory, indirect taxes/VAT, tax‑technology and digital tax.
• Description: Deloitte is a global professional services network renowned for its sizeable tax consulting offering. With over 150 countries of presence, its tax practice supports multinational clients with complex cross‑border tax structuring, digital tax‑automation tools, and M&A‑oriented tax due diligence linkage. Clients benefit from its full‑spectrum approach-from compliance to strategic tax planning-combined with deep industry and regional tax‑jurisdiction expertise.
• Key Features:
  • Comprehensive international tax footprint (many jurisdictions)
  • M&A tax advisory integrated with deal‑services capability
  • Tax‑technology & digital tools to automate compliance and risk
  • Strong in transfer pricing and indirect tax (VAT/GST)
  • Industry‑specialist tax teams (e.g., energy, tech, financial services)

2. PricewaterhouseCoopers (PwC)

• Founders: Samuel Lowell Price (1849) / Coopers & Lybrand legacy
• Founded Year: 1998 (merger of Price Waterhouse & Coopers & Lybrand)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax & legal services, global mobility tax, corporate tax strategy, tax risk & controversy, digital tax transformation, tax carve‑out and integration.
• Description: PwC is a global leader in tax consulting, offering clients a combined audit‑tax‑consulting ecosystem. Its tax practice helps enterprises navigate shifting tax regimes, embrace digital tax reporting, manage controversy and optimise tax strategy aligned with business transformation. The firm’s global network enables support for large multinationals, offering both compliance and strategic tax‑advisory services.
• Key Features:
  • End‑to‑end tax lifecycle support: compliance through strategy
  • Strong talent and global reach in 157+ countries
  • Digital tax tools (e‑invoicing, indirect tax automation)
  • Tax‑controversy and dispute‑resolution capability
  • Carve‑out/integration tax support in M&A contexts

3. Ernst & Young (EY)

• Founders: Arthur Young and Alwin C. Ernst (mergers in 1989)
• Founded Year: 1989 (modern form)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Global tax advisory, enterprise tax planning, digital & automated tax services, transfer‑pricing, tax risk assurance, transaction tax.
• Description: EY’s tax practice combines deep global coverage with an emphasis on innovation and digital tax services. It supports businesses in building tax‑operating models, adopting tax‑automation and handling transactional tax complexity. Its advisory work often links tax to business‑model transformation and technology‑enabled change, making it a go‑to for organisations facing disruptive tax environments.
• Key Features:
  • Tax‑operating‑model design and transformation
  • Digital tax automation and analytics platforms
  • Transaction‑tax advisory integrated with M&A
  • Transfer‑pricing and global mobility tax strength
  • Strong presence in emerging tax jurisdictions

4. KPMG

• Founders: William Barclay Peat, James Marwick, Roger Mitchell, Piet Klijnveld, Jaap Kraayenhof, Reinhard Goerdeler
• Founded Year: 1987 (merger forming KPMG Peat Marwick)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax services (corporate, international, indirect), tax risk & regulatory, transfer‑pricing, tax due diligence, tax‑technology enablement.
• Description: KPMG’s global tax consultancy helps firms address multi‑jurisdictional tax complexity with robust compliance and advisory frameworks. The firm emphasises risk governance, regulatory tax‑landscape monitoring and aligning tax strategy with business strategy. Clients particularly rely on KPMG for complex tax engagements where audit, advisory and tax converge.
• Key Features:
  • Global network in 145+ countries
  • Emphasis on tax‑risk governance and compliance culture
  • Strong in transfer‑pricing operations and documentation
  • Tax due diligence in deals with transactional focus
  • Integrated audit‑tax‑advisory offering

5. BDO International

• Founders: (Multiple founding firms; BDO stands for Binder Dijker Otte)
• Founded Year: 1963 (as international network)
• Headquarters: Brussels, Belgium
• Product/Service Categories: Tax advisory (corporate & international), indirect tax, private‑client tax, tax for mid‑market, tax compliance & reporting.
• Description: BDO International is a network of independent accounting and consulting firms offering strong tax‑advisory services to mid‑market companies. While not as large as the Big Four, BDO provides agile, regional tax support with global reach. Its tax teams specialise in helping growth companies, private equity‑owned firms and entrepreneurial businesses manage tax challenges across borders.
• Key Features:
  • Mid‑market focus with global footprint
  • Private‑client and owner‑managed business tax support
  • Cross‑border tax structuring for growth firms
  • Indirect tax and VAT services regionally strong
  • Cost‑competitive relative to large global firms

6. Grant Thornton

• Founders: Sir Angus Sterne, etc. (various)
• Founded Year: 1924 (original firms)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax consulting (corporate, transaction, international), tax controversy, private‑business tax, indirect tax & VAT.
• Description: Grant Thornton is a major professional services firm offering tax‑consulting services targeting mid‑sized enterprises and their international ambitions. Its tax practice covers advisory and compliance, with strength in transactions and growth company tax planning. The firm blends global resources with more personalised service, making it a good choice for companies that seek high‑touch tax consultancy rather than standard large‑firm scale.
• Key Features:
  • Focus on growth and mid‑sized enterprises
  • Transaction‑tax advisory (M&A, carve‑out)
  • Private‑business and owner‑managed business tax expertise
  • Global network with local responsiveness
  • Indirect tax/VAT advisory across jurisdictions

7. RSM International

• Founders: Originally multiple national firms (e.g., RSM McGladrey etc.)
• Founded Year: 1964 (as network)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax advisory (corporate & international), transfer‑pricing, private‑company tax services, indirect tax, expatriate tax.
• Description: RSM International is a major network serving primarily middle‑market companies, offering tax consultancy with global reach and flexible service delivery. Its tax advisory span covers international tax planning, expatriate and mobility tax, transfer‑pricing, and domestic compliance. For organisations outside the mega‑corporate tier, RSM provides a credible alternative to the largest firms.
• Key Features:
  • Middle‑market specialist with global coverage
  • Focus on private and owner‑managed businesses
  • International tax planning and expatriate tax services
  • Transfer‑pricing support for growing companies
  • Cost‑effective structure relative to Big Four

8. Mazars

• Founders: Robert Mazars (origin), various merged entities
• Founded Year: 1945 (as Mazars)
• Headquarters: Paris, France / London region presence
• Product/Service Categories: Tax consulting, global mobility tax, indirect tax/VAT, tax digitalisation, private‑client tax, regional tax advisory.
• Description: Mazars is an international audit, tax and advisory firm that provides tax consulting services with a strong European base and increasing global footprint. Its tax practice covers compliance, digital tax innovation, mobility tax and indirect tax. For organisations requiring European tax expertise with global reach, Mazars offers a balance of local‑market insight and international capability.
• Key Features:
  • Strong European market orientation with global link‑ups
  • Digital‑tax solutions and indirect‑tax advisory
  • Private‑client and expatriate tax advisory
  • Multilingual, multi‑jurisdiction tax teams
  • Flexible structure and competitive fees for mid‑market

9. Baker Tilly International

• Founders: (Network of independent member firms)
• Founded Year: 1987
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax consulting (corporate, indirect, mobility), M&A tax advisory, tax technology, cross‑border tax planning.
• Description: Baker Tilly is an international accounting‑advisory network whose tax consulting arm serves businesses that value local expertise in many jurisdictions. Its tax advisory services focus on mid‑market and growing firms requiring cross‑border support, M&A tax planning and digital tax automation. With 700 offices across ~143 territories, Baker Tilly offers breadth with a responsive local feel.
• Key Features:
  • Extensive global network of member‑firms (~700 offices)
  • Tax advisory tailored for growth and mid‑market companies
  • M&A tax planning and cross‑border support
  • Digital tax and indirect‑tax advisory capability
  • Fluent local‑jurisdiction service with global coordination

10. UHY International

• Founders: (Network of audit/tax firms)
• Founded Year: (Independent network)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax consulting (corporate, cross‑border, indirect), business‑tax advisory, tax compliance, private‑client tax.
• Description: UHY International is a network of independent accounting and tax firms operating in ~100 countries and over 340 major business centres. It offers tax‑consulting services that combine local market expertise with cross‑border coordination-ideal for companies seeking strong regional tax support with international reach.
• Key Features:
  • Presence in 100+ countries and 340+ business centres
  • Focus on tax advisory for cross‑border operations and regional players
  • Flexible network structure allowing local partner responsiveness
  • Indirect tax and private‑client tax competencies
  • Cost‑competitive option for international tax consulting

11. ETL Group

• Founders: (German‑tax advisory group)
• Founded Year: 1971
• Headquarters: Essen / Berlin, Germany
• Product/Service Categories: Tax and legal advice, auditing, management consultancy, tax compliance and planning services mainly in German‑speaking Europe.
• Description: ETL Group is Germany’s largest tax‑advisory and legal‑services group, employing 10,000+ staff and servicing approx. 200,000 clients. It specialises in German tax compliance, taxes for entrepreneurs, legal structures and provides management consultancy. For companies operating in Germany or Central Europe, ETL offers strong local‑tax expertise.
• Key Features:
  • Exceptionally strong German‑market tax and legal expertise
  • Large client base (200,000 clients) and significant staffing
  • Services tailored to entrepreneurs and family‑business tax needs
  • Integrated tax, legal, auditing and consultancy services
  • Ideal for German‑speaking jurisdictions and Central Europe

12. Ryan LLC

• Founders: John Ryan and others
• Founded Year: 1991
• Headquarters: Dallas, Texas, United States
• Product/Service Categories: Tax consulting (state & local tax, credits & incentives, global tax, M&A tax, tax controversy & litigation support).
• Description: Ryan LLC is a U.S.‑based tax consultancy that has become recognised globally for its expertise in state & local taxation (SALT), credits & incentives, and complex tax‑contingency matters. It serves clients in corporate tax planning, M&A tax issues and helps recover tax refunds. With its dynamic model, Ryan offers specialised tax‑advisory services distinct from the Big Four.
• Key Features:
  • Specialist in state & local tax and credits/incentives
  • Global tax consulting and M&A tax support
  • Tax‑contingency and litigation‑support capabilities
  • High‑value cost‑recovery focus (refunds, incentives)
  • Suitable for both U.S. domestic and global clients

13. Ecovis

• Founders: (International network origins)
• Founded Year: (Modern formation 2000s)
• Headquarters: Berlin, Germany
• Product/Service Categories: Tax, auditing, accounting and legal services in 90+ countries; tax consulting for international business, cross‑border tax structuring, SME tax services.
• Description: Ecovis is a global consulting firm specialising in tax, auditing, accounting and legal services in more than 90 countries. It stands out for its holistic integration of tax, legal, economic and accounting perspectives-particularly beneficial when international tax complexity or group structuring is involved.
• Key Features:
  • Service offering spans tax + legal + accounting
  • Global network in 90+ countries
  • Strong SME and mid‑market international tax support
  • Cross‑border structuring and group‑tax advisory
  • Local entrepreneurs’ tax services with global coordination

14. Andersen Global

• Founders: Mark Vorsatz (and former Arthur Andersen partners)
• Founded Year: 2002 (original WTAS, became Andersen Global in 2014)
• Headquarters: Chicago, Illinois, United States (global network)
• Product/Service Categories: Tax & legal advisory, global tax structuring, M&A tax, controversy & dispute‑resolution, private‑client tax.
• Description: Andersen Global is a network of tax and legal professionals that emerged from the legacy of Arthur Andersen. It focuses on tax and legal‑advisory work, offering tax‑consulting solutions for high‑net‑worth individuals, multinational enterprises and cross‑border transactions. It distinguishes itself with leaner structure and specialist focus compared to large audit‑dominated firms.
• Key Features:
  • Global tax‑legal advisory network with lean model
  • Cross‑border tax structuring and private‑client tax focus
  • M&A tax and dispute‑resolution strengths
  • Independent from large audit networks (conflict‑free model)
  • Attractive for firms seeking tax‑legal specialists

15. Crowe Global

• Founders: (Network of member firms)
• Founded Year: 1915 (Crowe Horwath U.S. origins)
• Headquarters: Chicago, Illinois, United States (global network across 130+ countries)
• Product/Service Categories: Corporate tax consulting, international tax services, tax compliance, transfer pricing, private‑client tax.
• Description: Crowe Global (formerly Crowe Horwath) is a global accounting and consulting network offering tax‑advisory services tailored to enterprises across sectors and geographies. Its tax offering includes cross‑border tax planning, transfer‑pricing, and private‑client tax for family‑owned or privately‑held businesses seeking international reach.
• Key Features:
  • Global network in 130+ countries
  • Cross‑border tax advisory and transfer‑pricing services
  • Private‑client and family‑business tax support
  • Mid‑market orientation with international capability
  • Value‑driven regional support with global coordination

16. Haines Watts

• Founders: (UK tax/accounting origin)
• Founded Year: (20th‑century UK firm)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax planning for businesses, indirect tax (VAT/Customs), private‑client tax, international tax advisory for UK‑domestic and cross‑border businesses.
• Description: Haines Watts is a UK‑based tax and accounting firm, ranked among the top tax‑advisory firms in the UK. It provides tax‑planning services, VAT and customs advisory, and international tax consulting for businesses with global exposure. Particularly suited to UK‑based companies expanding offshore or internationally.
• Key Features:
  • Strong UK‑tax advisory and indirect‑tax capability
  • Focus on business growth and cross‑border operations
  • Private‑client and family‑business tax support
  • VAT/customs advisory for international trade
  • Personalised service in UK‑regional centres

17. Saffery Champness

• Founders: (UK firm heritage)
• Founded Year: (19th‑century origin)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax advisory (corporate, owner‑managed business), international tax, private‑client tax, wealth‑structuring, VAT & indirect tax.
• Description: Saffery Champness is a specialist UK accounting and tax advisory firm serving entrepreneurial businesses, families and owner‑managed groups. Its tax consultancy focuses on structuring, cross‑border tax, private‑client tax, and indirect‑tax matters. Those seeking bespoke tax advice in the UK and internationally may find the firm’s model appealing.
• Key Features:
  • Boutique tax‑advisory focused on entrepreneurs and owner‑managed businesses
  • International tax planning and wealth‑structuring capability
  • Private‑client tax for high‑net‑worth individuals
  • VAT and indirect‑tax support for cross‑border trade
  • Personal partner engagement model

18. PKF International

• Founders: (Network of independent firms)
• Founded Year: 1969 (as PKF International)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax consulting, international tax services, indirect taxes, private‑client tax, compliance outsourcing.
• Description: PKF International is a global network offering tax‑advisory services with strong reach in emerging markets and fit for mid‑sized international businesses. Its tax practice provides cross‑border tax structuring, compliance outsourcing and indirect‑tax advisory. Firms growing internationally or moving into emerging economies may find PKF a relevant option.
• Key Features:
  • Established global network with strength in emerging markets
  • Cross‑border tax structure and compliance outsourcing
  • Indirect‑tax and VAT advisory for trading businesses
  • Private‑client tax support for international individuals
  • Mid‑market orientation with global capability

19. MOORE Global

• Founders: (Network of independent accounting firms)
• Founded Year: (As a network formed early‑2000s)
• Headquarters: London, England, United Kingdom
• Product/Service Categories: Tax advisory (corporate & international), private‑client tax, international mobility tax, indirect tax, tax‑compliance services.
• Description: MOORE Global is an international accounting and advisory network with a pronounced tax‑advisory arm. Their tax teams work across corporate tax, private‑client, mobility and indirect taxes. For businesses and individuals moving internationally who require a consistent global tax‑service model, MOORE offers a cohesive network.
• Key Features:
  • Global network supporting over 100 countries
  • Broad tax‑service suite: corporate, mobil­ity, indirect, private‑client
  • Focus on clients in growth, mobility and global operations
  • Network coordination with local tax‑expert involvement
  • Often cost‑effective alternative to largest firms

20. Crowe Horwath (US)

• Founders: (US national firm, part of Crowe Global network)
• Founded Year: 1942 (US origins)
• Headquarters: Chicago, Illinois, United States
• Product/Service Categories: Corporate tax consulting, international tax, transfer pricing, private‑client tax, tax controversy and litigation.
• Description: Crowe Horwath (part of Crowe Global) delivers tax‑consulting services to client segments ranging from large corporates to privately‑held firms. Its tax advisory covers corporate international tax, transfer‑pricing, and private‑client tax, as well as tax‑controversy. For U.S.‑domiciled companies expanding globally-or non‑U.S. companies operating in the U.S.-Crowe offers relevant tax‑advisory capability.
• Key Features:
  • U.S. tax‑expertise plus global network reach
  • Transfer‑pricing and international‑tax consulting strength
  • Private‑client tax and wealth‑structuring capability
  • Tax‑controversy and litigation‑support services
  • Dedicated teams for mid‑sized and privately‑held firms

Conclusion

Tax consulting in today’s landscape demands a blend of regulatory expertise, global‑jurisdictional reach, digital‑tax capability, and strategic alignment with business transformation. The 20 firms profiled above span from global giants (e.g., Deloitte, PwC, EY, KPMG) to specialised networks and regional tax advisors.

When selecting a tax‑consulting partner, consider the following: your organisational size and growth trajectory, the complexity of your tax footprint (domestic vs. global), the level of tax risk or controversy you face, the need for digital‑tax transformation, and your budget for advisory support. Global networks bring scale and breadth; mid‑market and regional firms may offer more focused service and cost‑effectiveness.

By matching your tax‑consulting needs with the right firm-one whose strengths align with your strategy-you position your organisation for robust tax compliance, efficient tax‑strategy execution and clearer business value. The firms listed here are well‑equipped to deliver that, depending on your specific requirements.