Contentious Tax

Our dedicated contentious tax practice combines outstanding technical ability, strategic oversight and commercial understanding to steer our clients through the resolution and litigation of tax disputes. Our team draws on the expertise of specialist tax lawyers from across our international offices and Simmons & Simmons’ wider Litigation, Investigations and Competition and Regulatory practices.

Our Practice

As tax authorities around the world take an increasingly robust stance on tax compliance and law enforcement, businesses have a sharper focus on how tax controversies are managed, with brand and reputational risk being increasingly important factors. We understand the importance of managing tax disputes successfully and cost effectively.

The contentious tax practice at Simmons & Simmons:

  • acts on the full range of civil and criminal tax disputes and contentious issues, providing liability and quantum advice and representing clients in litigation and negotiation with revenue authorities
  • advises on all corporate, indirect, personal and environmental taxes
  • helps clients balance the risk of contentious tax positions with the impact on external stakeholders and relationships.


Tax litigation and dispute resolution

  • preventing, managing and resolving tax disputes through litigation, but also through all forms of alternative tax dispute resolution, including mediation and arbitration

Contentious advisory

  • advising on all contentious tax matters and understanding how managing litigation risk can help clients to pursue tax opportunities

Claims filing and management

  • assisting clients to pursue claims against revenue authorities

Tax investigations and fraud

  • handling tax investigations concerning serious tax avoidance or evasion dealt with as a civil or criminal matter and prosecutions

Commercial tax disputes

  • assisting clients in civil litigation where tax is a component of the dispute , such as where tax liabilities go to quantum, and in professional negligence matters

Tax efficient structuring and implementation

  • planning and implementing tax efficient structures to ensure that they are robust to legal challenge, and reviewing the implementation of existing structures

Specialist expertise

Tax forms a crucial element in the commercial life of all businesses and will often determine the structure of more complex transactions.

Our team of international tax lawyers advises on the full range of corporate tax matters and is regularly involved in complex tax planning and tax structuring arrangements. We have particular experience in the following areas:

Corporate transactions

  • mergers and acquisitions, reconstructions, joint ventures and buyouts 

Banking and capital markets

  • loan facilities, equity and bond issues and foreign exchange, derivatives and other financial instruments

Structured finance

  • securitisation and other structured and asset finance transactions where the taxation treatment is of paramount importance to success

Investment funds

  • advising in relation to tax issues on the establishment and operation of investment management businesses and the launch and operation of funds, both in the traditional and alternative sectors. By choosing the most appropriate jurisdictions and structure for the fund, returns can be maximised

Real estate

  • acquisition and development transactions, choice of investment vehicle and minimising transaction taxes

Commercial transactions

  • service agreements, distribution, manufacturing and supply contracts, partnerships and privatisations

Inward investment

  • structuring of capital investment and business operations to ensure tax efficiency


  • implementation and structuring of both IT and business process outsourcing proposals in the banking, asset management and insurance sectors, advising both customers and providers

Employee remuneration

  • tax efficient incentives to employees and cross-border share and bonus schemes

VAT and indirect taxes

  • we have an established reputation as advisers on VAT and other indirect taxes

Contentious tax matters

  • negotiating with tax authorities, conducting tax litigation for both direct and indirect tax matters, resolving tax disputes through Alternative Dispute Resolution, tax fraud and investigations and acting on commercial disputes concerning tax

Tax policy

  • advising commercial clients and government bodies on a range of national and international tax policy matters. In addition, we are active members of professional and industry associations and are regularly involved in making representations on tax matters. By way of example, we are heavily involved in consultations on proposals for a multilateral EU Financial Transaction Tax.