CASE STUDY · UK SRT

When five UK days put £3.1m at risk

A public tribunal decision shows why UK residence tracking is not just a spreadsheet exercise.

Updated 15 May 2026 · Educational content, not tax advice

In the Upper Tribunal decision commonly referred to as A Taxpayer v HMRC [2023] UKUT 00182 (TCC), the taxpayer’s UK residence position turned on whether five UK nights could be ignored under the Statutory Residence Test exceptional-circumstances rule.

The short version

What went wrong

The taxpayer argued that the additional UK days should be disregarded because she was in the UK due to exceptional circumstances involving her twin sister and the care of minor children. The First-tier Tribunal accepted that argument, but HMRC appealed.

The Upper Tribunal overturned the First-tier Tribunal decision. It held that the relevant exceptional-circumstances test had not been met, so the disputed days could not be ignored. However, the litigation did not end there: in 2025, the Court of Appeal allowed the taxpayer’s appeal and restored the First-tier Tribunal decision. The commercial lesson remains that a small number of disputed days can put a major tax position into years of enquiry and litigation.

Why this matters for internationally mobile families

The lesson is not simply “do not exceed 45 days”. Different SRT thresholds apply depending on residence history and UK ties. The deeper lesson is that every day-count assumption needs to be visible, documented and adviser-reviewable before the tax return is filed.

When the disputed number is small, the financial consequence can still be large. In this case, five days sat between a non-resident filing position and a potential UK-resident outcome with a multi-million-pound HMRC amendment. Even where the taxpayer ultimately succeeds, the cost, delay and uncertainty are exactly what better records are meant to reduce.

Atrium angle: Atrium helps keep confirmed journeys, day-count assumptions and supporting evidence in one place, so clients and advisers can review the factual record before a small day-count issue becomes a large tax dispute.

Useful search intents

UK tax residence case study, Statutory Residence Test tribunal, HMRC day count dispute, exceptional circumstances SRT, UK residence 45 days tax.

Source note

This article summarises public reporting, the Upper Tribunal decision A Taxpayer v HMRC [2023] UKUT 00182 (TCC), and later reporting on the Court of Appeal decision A Taxpayer v HMRC [2025] EWCA Civ 106. It is not legal or tax advice.