Hi,
For the purpose of the Statutory Residence Test, HMRC consider that a person’s home is a place that a reasonable onlooker with knowledge of the material facts would regard as that person’s home.
Case 4 woud deal with someone who did not meet the only home test at the start of the tax year, but at some point in that tax year they do meet the only home test and continue to do so until the end of that tax year, wheareas, case relates to an individual, who has no home in the UK but at some point during the tax year they start to have a home in the UK and they meet the criteria for Case 8.
RDRM12150 - Residence: The SRT: Split year treatment: Case 4: Starting to have a home in the UK only
Thank you.