Readers’ forum: Split year treatment

My client is an American citizen who arrived in the UK in September 2019. Therefore I am expecting him to be considered UK-resident under the statutory residence test for 2020 albeit entitled to claim split year treatment. He was self-employed in the US and has continued to work on a self-employed basis following his arrival in the UK. We are now considering whether a 2020 UK self-assessment tax return is required.

His profits of about £25 000 are subject to US tax which we have calculated covers any UK tax that may arise. However the question of National Insurance vexes me. I can see that class 2 does not apply for the first 26 weeks after arrival but I cannot ascertain whether class 4 applies. A class 4 liability will necessitate a return for 2020 and I do not believe that US...