Drilling down: Mr Tooth and the tax return

A complex Supreme Court case in 2021 ended in taxpayer victory — and two takeaway messages.

1. Importance of full disclosure to HMRC. Unable to get software to enter key information in the right box on the right page of his self assessment tax return, Mr Tooth and his advisers decided to crack the system. Using an ‘obviously artificial’ tax reference number, 99999 99999, they put it on the partnership page of the return, instead. Detailed disclosure was then made in the white space on the return.

HMRC maintained that the return was deliberately inaccurate. Deliberate inaccuracy is the green light for HMRC to assess any loss of tax for up to 20 years after the end of the tax year concerned: it also opens the door to higher penalties. The Court, however, held that Mr Tooth had no deliberate intention to mislead, but had done his best ‘in the context of an intractable online form’.

2. HMRC bite. The Court upheld HMRC in the important area of discovery assessments. These can be used where HMRC believes the wrong amount of tax has been assessed. The Tooth case makes it easier for HMRC to access extended time limits, even where it has delayed using available information, to raise additional tax bills, subject to the normal statutory time limits and principles of public law.

Ouch.