Giles has represented clients in litigation before the tax tribunals through to the UK Supreme Court. He has appeared as an advocate for many clients before the Court of Justice of the European Union. Throughout his career he has specialised on the EU law aspects of indirect taxes and since Brexit has advised many businesses on its impact. Giles was at the vanguard of UK tax mediation, is a CEDR trained meditator and has successfully resolved many tax disputes without the need for litigation.

Giles advises on all aspects of VAT and indirect taxes. He has acted for multinationals and private companies across financial services, TMT, hospitality and leisure as well as the government sector and smaller businesses. Giles advises overseas businesses on doing business in the UK, particular in the e-commerce sector. He has specialist knowledge of how HMRC and its lawyers within the Solicitor’s Office, the judges of the First-tier Tribunal and the Upper Tribunal operate.


  • Fleming and Condé Nast v HMRC before the House of Lords: paved the way for a change in the law allowing taxpayers to make retrospective claims for VAT, totalling billions since 1973.
  • MG Rover Group Ltd and Others v HMRC at the Court of Appeal: involved a dispute in relation to a VAT claim of £56m and whether it was repayable to BMW or MG Rover. This has become one of the leading cases on the operation of UK VAT groups.
  • Acting for Aozora GMAC Investment Ltd in complex litigation resulting in a leading Court of Appeal decision on judicial review and legitimate expectation, as well as a successful appeal before the Upper Tribunal on substantive tax issues concerning US/UK tax relief.
  • Acting for a US investment bank in relation to a partial exemption dispute unlocked by judicial review.
  • Acting for a multinational travel company in relation to a judicial review and appeal relating to recoverability of input tax.
  • Acting for a leading financial services provider in relation to VAT liability of its services and VAT group eligibility.


Giles is recognised by The Legal 500 for his expertise in tax disputes, VAT and indirect tax, and for his specialism in EU cases. He is also recognised by Chambers Global for his contentious tax expertise.


Giles qualified into the Solicitor’s Office of HMRC; he is also qualified as a barrister. He has worked previously at Arthur Andersen, Deloitte and Eversheds Sutherland, where he was UK Head of Indirect Tax and Litigation and Controversy Tax. Giles joined Stewarts in November 2023.

Accreditations and Memberships

Giles is a CEDR trained mediator and a member of the St Paul’s Chapter of the VAT Practitioner’s Group. He is also a member of the Investment Association VAT committee and the British Property Federation VAT committee.