Third party information may be wanted
In the normal case you should ask the taxpayer under enquiry for the information first. You should only approach third parties where you need corroboration of information that
If you do approach a third party your request for information
should be reasonable and you should not ask for any information
that may be unduly onerous to provide.
When a third party supplies information to you must not tell them about the use to which the information is being put.