Information and inspection powers: Schedule 36 FA 2008: taxpayer information notices after assessments or closure notices have been issued - tribunal directions
Where you are unable to issue a taxpayer notice in order to obtain information relevant to an appeal, you should consider seeking the information through the tribunal’s own powers.
Rule 5 of the tribunal rules allows the tribunal to make directions and require a party to the appeal proceedings or other person to provide documents, information or submissions to the tribunal or one of the parties. Rule 3 also encourages the tribunal to assist in finding an alternative dispute, resolution process. So it might be possible to get a direction from the tribunal either requiring the taxpayer to produce certain information or, more generally, requiring both parties to work towards a Section 56 TMA with exchange of information and documents as needed. (Such a direction ought to set a time limit for coming back to the tribunal if agreement could not be reached).