INTM830300 - Residence & non-UK domiciles: Formally disputed
As part of the certification process, the member of the relevant professional body will have needed to affirm that, to the best of their knowledge, the domicile status of the individual was not “formally disputed” by HMRC.
In this case, “formally disputed” means where a domicile issue has been specifically raised under formal enquiry (usually S9A TMA 1970) and the matter has not been resolved.