CH254530 | How to do a compliance check: using inspection powers: inspection at a person’s home: when inspection is not allowed
From HM Revenue & Customs · Compliance Handbook
You do not have powers to visit homes used in connection with a business in the following circumstances:
a director or employee is working from home
a director or employee has temporarily taken some records home from other business premises to work on
premises, including rooms in a house, are rented to another person and used solely by them as their home
On the other hand, where a partner in a business works partly from home, that home will be business premises of the partnership. But a visit would only be justified in exceptional circumstances, perhaps to support a challenge to the amount of domestic expenses claimed as a business deduction.