HMRC Tax Determination
Where a taxpayer does not file tax returns by the due date despite having been given notice to file, HMRC have a right to raise ‘determinations’ under s 28C of the Taxes Management Act 1970. Such a determination has effect as if it were a self-assessment (in other words, it stands in place of a self-assessed tax return and can be enforced by HMRC).
No Appeal Process
There is no appeal against such a determination but it can be displaced by filing a tax return. A determination, or a tax return displacing a determination, must be made/filed within 3 years from the due date for the tax return.
Discovery Assessments
Discovery assessments arise under Section 29(1) of the Taxes Management Act 1970. Unlike determinations, there is a right of appeal against such assessments.
Appeal Provision
There is no provision that allows a Discovery Assessment to be displaced by a tax return.
Determinations can be displaced by a tax return but cannot be appealed; assessments can be appealed but (it logically follows) cannot be displaced by a tax return.






