CH225670 | How to do a compliance check: information powers: third party notice: partnerships: notice to a partner whose tax position is being checked, to check one other partner
From HM Revenue & Customs · Compliance Handbook
When you give a notice to a partner, whose tax position is being checked, to check the tax position of one other partner in their capacity as a partner, see CH23720.
The notice you issue is a combined taxpayer (for the recipient partner) and third party notice (for the other partner). SEES Forms and Letters contains a combined notice - IIP22.
Your notice must name the other partner.
You do not need to give a copy of your notice to the named partner.
You do not need approval from the named partner.
You must ensure that the conditions for a taxpayer notice, see CH23520, are met in relation to the recipient of your notice.
The recipient partner has taxpayer appeal rights against the notice as it relates to their tax position and the tax position of the named partner.
If you seek the tribunal’s approval you do not need to give a summary of your reasons to either partner although you may if you consider it appropriate. You should consider carefully and respond positively to any request by a partner for a summary of reasons, provided that doing so will not jeopardise your check.