I am somewhat surprised that your accountant has not answered this question. If you haven't asked it of him; I would respectfully suggest that you do so.
Being of a suspicious mind, it occcurs to me that perhaps you are a revenue employee embarked upon a fishing trip. If so, please be so kind as to tell me whether the following, issued in good faith, would be an accurate assessment of the situation.
I think that a clever revenuer might argue thus:
You depart the UK working for your UK based employer and remain continuously in gainful employment, on duty, split or otherwise, until you return to the UK the following day. Therefore the employment has continuously been generated within the UK as the servant of a British carrier and we would deem you ordinarily resident for that period of time even though you were not actually in the country for the entire period.
Furthermore, such voyages to and from the UK, whether or not involved in your employment indicate a regular pattern which is possibly even predictable and as such the ninety day rule can be applied flexibly, to their advantage, epecially if you are up on its limits anyway.
(Perhaps you could check case law on this point.)
I feel absolutely certain that said clever and crafty revenuer would try to make such an arguement stick. Since you would then have to prove that his assessment was incorrect, it would, at the least, be expensive for you.
I think you play with fire here. Of course they will never find out? But if they did and even if they determined you were not acting fraudulently they can go back six years, take the back tax, apply compounded interest and whack a 100% fine on top. Well, I think that's right but anyway, it's a reasonable indication of how expensive it could become!
Should add that I am not an accountant but have enough experience to want to stay legally on the right side of the little man - especially right now when old Gordon is hammering away at Channel Island accounts and non resident/domiciliaries.
