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