Under FA 2008, Sch. 36, para.2 a written notice can be sent to a person requiring them to:-
if the information or document is reasonably required for the purpose of checking the tax position of another person – a third party notice.
HMRC will only issue a third party notice if they cannot get the information or documents by way of a taxpayer notice or if they suspect that there might be collusion between the taxpayer and the third party.
There is a time-limit for issuing a third party notice in respect of a taxpayer who has died. Para. 22 stipulates that a notice for checking the tax position of a dead person cannot be issued more than 4 years after the person’s death.
The third party notice must name the person whose tax position is being checked unless the notice was approved by the Tribunal and they were satisfied that it should not do so.
A copy of the notice must be sent to the taxpayer unless this condition is disapplied by the Tribunal.