Tax Expert Witness Services for UK Solicitors & Tax Litigation Counsel
When a tax dispute reaches the First-tier Tribunal, Upper Tribunal, or Crown Court, the technical tax analysis must be independently verified by a qualified expert. TaxExpertWitness.co.uk connects UK solicitors and tax litigation counsel with qualified tax expert witnesses, specialists in HMRC investigation methodology, tribunal procedure, and independent tax technical opinion.
Independent tax expert witness referrals
Where tax disputes are argued
HMRC enquiries
Challenges to assessments, discovery and penalty methodology.
Tribunals and courts
Evidence for the First-tier Tribunal, Upper Tribunal and above.
Customs and VAT
Indirect tax, duty and MTIC disputes with HMRC.
Technical opinion
Independent analysis of the law as it applies to the facts.
What Our Tax Expert Witnesses Cover
Technical Tax Opinion
Independent technical tax opinions addressing whether HMRC's tax analysis is correct, what the correct tax treatment sho…
Read more →HMRC Methodology Challenge
Expert review and challenge of HMRC's financial reconstruction methodology, including cases where HMRC relied on flawed …
Read more →VAT Dispute Expert Evidence
Expert evidence for VAT disputes including MTIC fraud input tax denial, knowledge test analysis under Mobilx v HMRC, and…
Read more →Transfer Pricing Expert Evidence
Arm's length analysis, comparables review, and OECD method selection for transfer pricing disputes, particularly importa…
Read more →IHT & CGT Valuation Disputes
Independent valuation opinions for IHT business property relief disputes, CGT share disposal valuations, and challenges …
Read more →Employment Related Securities
Expert evidence for ERS disputes under ITEPA 2003, including growth shares, restricted share plans, EMI options, and s43…
Read more →Tax Professional Negligence
Expert opinions on standard of care in tax advice, whether advice fell below the required standard, the correct advice t…
Read more →COP8 / COP9 Support
Expert support for HMRC Code of Practice 8 and Code of Practice 9 investigations, reviewing HMRC methodology before disc…
Read more →UK Tax Disputes: Key 2025 to 2026 Facts
| Fact | Figure | Source |
|---|---|---|
| FTT cases listed for hearing 2025 to 26 | Thousands | HMCTS Statistics |
| Time from appeal to FTT hearing | Typically 2 to 3 years | Slaughter and May, 2024 |
| HMRC transfer pricing yield increase | Significant rise 2025 | Jon Preshaw Tax, March 2026 |
| FTT jurisdiction | Income tax, CT, CGT, IHT, VAT, SDLT, NIC | HMCTS |
| Upper Tribunal role | Appeal on points of law from FTT | HMCTS |
| HMRC v Harte [2026] | HMRC's extended time limit use criticised | UKUT 2026 |
| Expert evidence framework | CPR Part 35 / FTT Rules | Civil Procedure Rules |
Sources: HMCTS Annual Statistics; Jon Preshaw Tax Disputes Newsletter March 2026; HMRC v Harte [2026] UKUT 00112.
Who Needs a Tax Expert Witness?
Tax Litigation Counsel
You need independent technical tax opinion to support or challenge HMRC's position before the FTT or Upper Tribunal.
Learn more →Forensic Accountants
Your financial evidence is complete, but the case also raises technical tax analysis questions outside forensic accounting expertise.
Learn more →Taxpayers' Advisers
Your client faces a COP8 or COP9 investigation and needs independent expert review of HMRC's methodology.
Learn more →A tax expert witness is fundamentally different from a forensic accountant. While forensic accountants focus on financial numbers, tax expert witnesses provide independent technical opinions on whether the correct tax analysis was applied. Learn what a tax expert witness does →
United Kingdom Service Scope
This website covers tax expert witness instruction for disputes within the United Kingdom only. Our content, guides, and expert referral service address HMRC assessments and enquiries, the First-tier Tribunal (Tax Chamber), Upper Tribunal, Court of Appeal, and civil court proceedings where UK tax law applies across England, Wales, Scotland, and Northern Ireland.
Expert witnesses introduced through this service are qualified in UK tax practice, familiar with HMRC manuals and published guidance, and experienced in giving evidence under CPR Part 35 and FTT Rules. We do not cover US Internal Revenue Service disputes, EU member state tax proceedings outside the UK, or other non-UK jurisdictions.
The .co.uk domain reflects this focus: all dispute types, tribunal guides, and investigation procedures described here assume a UK tax context. For an overview of the UK tax dispute landscape, see Tax Disputes Explained.
Instruct a tax expert witness
Tell us about your UK tax dispute and we will match you with a qualified expert witness experienced in HMRC enquiries and tribunal proceedings.