ARTG8060 - First-tier and Upper Tribunals: Introduction: Definitions
An applicant is a person making an application to the Tribunal, such as applying to be allowed to bring a late appeal or for permission to an issue an information notice.
An appellant is the person who starts proceedings, by appealing to the tribunal. This definition can include HMRC if we bring proceedings, for example by appealing against the decision of the FTT.
A respondent means HMRC, where the appellant is not HMRC. If HMRC brings the proceedings the respondent is the person against whom proceedings are brought or to whom proceedings relate.
A party to the proceedings is a person who is an appellant or respondent in proceedings before the tribunal