Readers' forum : Mixing it up

I have a non-dom client who came to the UK for the first time during 2015-16. That was a split year and he has been resident here since. He has claimed the remittance basis since he arrived although he currently does not need to pay this charge because he has not been in the UK for seven of the past nine years.

Before arriving my client sent funds of £2m to the UK. This was ‘clean capital’ because although they contained foreign income and gains they were ‘pre-arrival’ funds which had arisen before he became resident. He still has some funds offshore in a mixed account. That account contains historical income and gains which arose before he came to the UK and also foreign income and gains which have arisen since he became UK resident.

My question is for the purpose of the cleansing...