The rules for the UK are set out pretty clearly in the statutory residence test [1]. It covers all such cases in more detail than you ever wanted to know :) Wh

The rules for the UK are set out pretty clearly in the statutory residence test [1]. It covers all such cases in more detail than you ever wanted to know :) What causes difficulties though is that the rules in different countries, even if clearly defined, can contradict each other on the question of tax residency. So you may well be liable to pay taxes in two (or more) countries at the same time. You may even have to pay taxes in both countries on the same income or gains, unless there is a double taxation agreement that allows you to offset some of those taxes against each other [2] [1] https://www.gov.uk/hmrc-internal-manuals/residence-domicile-and-remittance-basis/rdrm11000 https://www.gov.uk/hmrc-internal-manuals/residence-domicile-... [2] https://www.gov.uk/government/collections/tax-treaties https://www.gov.uk/government/collections/tax-treaties