CH225050 - How to do a compliance check: information powers: third party notice: what is a third party notice
A third party notice is a written notice to a person requiring them to provide information or produce documents reasonably required to check the tax position of another person whose identity you know.
Before you consider giving a third party notice you should discuss your course of action with your line manager.
You may need tribunal approval before you can give a third party notice and if tribunal approval is required you will need the agreement of an authorised officer, see CH225450.
A template IT01 in SEES Forms and Letters is available for you to make your report to an authorised officer. The authorised officer may use template IT02 in SEES Forms and Letters to reply.