Expert tax dispute resolution.
Specialists in HMRC investigations, enquiries and disputes.
Jon Preshaw Tax Ltd is an independent practice of former HMRC and Big 4 tax experts.
Managing HMRC Investigations
Making Disclosures to HMRC
Resolving Disputes with HMRC
Services for Professional Advisers
Proactively Managing Tax Risk
Advising on HMRC Powers and Procedures
We’ve sat on both sides of the table, so however serious or sensitive your situation, we’re here to help.
Latest updates and insights from our experts in tax dispute resolution.
Tax Disputes and Investigations – March 2026
In this edition, we cover a range of significant developments in UK tax disputes and investigations. We share our recent experience on MTIC and HMRC internal reviews, and analyse the First-tier Tribunal's striking findings in HMRC v Harte, where HMRC’s approach to...
Code of Practice 9 (COP9)
Receiving a Code of Practice 9 (COP9) letter from HMRC is a serious matter that requires immediate attention. This letter indicates that HMRC suspects deliberate tax fraud has taken place and initiates a formal investigation. How you respond in the coming weeks can...
Tax Disputes and Investigations – December 2025
This newsletter picks up a number of issues which arose from the November budget which will be of particular interest to those involved in tax disputes. Additionally, we have focussed on some new ‘Guidelines for Compliance’...
Tax Disputes and Investigations – July 2025
HMRC reactivates enquiries into unallowable purpose Ben Proctor HMRC has been writing to taxpayers with open enquiries involving the unallowable purpose rule at Section 441 CTA 2009. The letters invite taxpayers to reconsider their position in light of three Court of...