I stand by what I said, and I did not intend to imply that it is impossible to shed UK domicile. So, yes, with apologies for perhaps creating anxiety, let me give my reading of the rules. Whilst there are inevitably tweaks and wrinkles, but the only way for someone (whose domicile of origin was in the UK) to lose their UK Domicile is via the explicit and clearly stated15/20 year rule......ie a very long time. In my view, timescales such as that cannot be relied upon where tax planning is concerned.

I believe you may be suggesting that there are two different rules for the same situation, or have I misread this? How can it be that you would be a non domiciled person after both three years and also 15 years? No, I think you will find that the three year rule refers to uk returners, not UK leavers. In other words, after you have become non domiciled by the 15/20 year rule, should you return to the UK you will be deemed domiciled in the UK after a short grace period. That is the three years you mentioned.

i am most certainly not an IHT expert, but I do think your advisers have got it dramatically wrong.