This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Compliance Handbook

Information & Inspection Powers: Information Notices: Appeals: Meaning of 'unduly onerous'

Any notice to a person that requires information or documents for the purpose of checking another person’s tax position is likely to impose a burden on the recipient of the notice.

The most likely burden will be in the person’s time needed to comply with the notice and the cost of doing so.

Careful consideration must be given to whether that burden is reasonable and proportionate compared with your need to check the tax position, see CH21360.

Wherever possible, the person who will receive the notice should be given the opportunity to comment on the extent of the burden and those representations should be carefully balanced against the benefits the information or documents will bring to the progress of the check.

A notice or a requirement in a notice will be unduly onerous if the burden on the person receiving the notice is disproportionately greater than the benefit expected to be gained from having the information or documents in question.