EIM42207 | Employment income: basis of assessment for general earnings: employees who are, or have been, not resident or not domiciled in the United Kingdom
From HM Revenue & Customs · Employment Income Manual
Chapters 4 and 5 of Part 2 ITEPA 2003
If an employee or office holder receives earnings for a year when they are (or were) not resident or not domiciled in the United Kingdom, the amount received may not be, or may only partly be, taxable. Detailed guidance is at EIM40001 onwards. In general you will find that, in cases involving non-UK residence or domicile:
Remember that it is the employee’s residence and domicile status in the year that the earnings are for that determines whether (or to what extent) the earnings are taxable (see EIM42201).