K5: Unappealable decisions
“An appeal may be brought against - …(d) any assessment to tax which is not a self-assessment.” (TMA 1970 s.31(1)(d))
“…it is not open to a taxpayer to appeal against their own self-assessment – s 31(1)(d) TMA.” (Norman v. HMRC  UKFTT 303 (TC), Annex 2, §21)
Section 28C determination in default of return
“a taxpayer has a remedy for incorrect amounts which he may pursue by submitting a return and self-assessment. Since the self-assessment supersedes and cancels out the determination there is no need for a right of appeal against amounts in the determination…But what can a taxpayer do when the officers of HMRC seek to collect the tax they say is due under an invalid determination…The answer, it seems to us, is the same as would be the case for any other illegal demand. He may contest the demand in the forum HMRC seek to enforce it. If necessary he might institute judicial review proceedings in the High Court for a declaration that the determination is a nullity.” (Bartram v. HMRC  UKFTT 471 (TC), §§28…31…32; approved by  UKUT 184 (TCC), §57).
Consequential amendment to partner's tax return under s.28B(4)
" In summary, I do not consider that the decision in Unison provides any basis for me to depart from the conclusion of the Upper Tribunal in Reid and other decisions noted above that a s28B(4) notice is not a closure notice and cannot be appealed under s31 TMA 1970. Accordingly, this Tribunal has no jurisdiction in respect of the appeal and the application to strike out is granted." (Mathieson v. HMRC  UKFTT 11 (TC), Judge Fairpo)
Decision not to admit a direct tax claim that is not in required form
FTT will decide if claim is in required form, but if it is not, no appeal against refusal
" Ms McDonald quite properly accepts that HMRC, rather than seeking clarification as to whether it should have assumed that a negligible value claim was being made, ought to have responded to the Accountants letter of 6 September 2018 by explaining, in accordance with its own guidance, what was needed to put the claim in the proper form and set out the information needed.
 However, as to whether or not the claim is in the required “form” and HMRC’s failure to notify Mr Williams of how it could be corrected to comply, is in the absence of a right of appeal under s 31 TMA, a matter for HMRC (and possibly a formal complaint, reference to the Adjudicator and/or judicial review) rather than the Tribunal.
 The applicable legislation, s 31 TMA, does not contain any right of appeal against HMRC’s decision not to admit a negligible value claim that is not in the required form and consequently not valid. Given that the Tribunal’s jurisdiction is governed by that legislation, it follows that the Tribunal does not have the jurisdiction to determine this issue or consider the conduct of HMRC not to allow the claim or refer the appellant to the appropriate guidance." (Williams v. HMRC  UKFTT 429 (TC), Judge Brooks)
Decision under disguised remuneration voluntary repayment scheme regs
" As I have already described, neither Finance Act 2020 nor the terms of the Disguised Remuneration Voluntary Repayment Scheme make any mention of any right of appeal to the First-Tier Tribunal. The Tribunal does not therefore have jurisdiction in relation to Mr Lambourne’s appeal and it must therefore be struck out in accordance with rule 8(2)(a) of the Tribunal rules." (Lambourne v. HMRC  UKFTT 466 (TC), Judge Vos)