c Your absence from the UK and your employment abroad both last for at least a whole tax year (April to April) During your absence any visits you make to the UK total less than 183 days in any tax year, and - the length of each stay, on the average, is less than 91 days per tax year. (The average is taken over the period of absence up to four years. Any days spent in the UK because of exceptional circumstances beyond your control, for example the illness of yourself or a member of your immediate family, are not normally counted for this purpose.)
Offshore Finance Guide Continued - Conditions
If you meet all the above conditions, you are treated as not resident and not ordinarily resident in the UK from the day after you leave the UK to the day before you return to the UK at the end of your employment abroad. You are treated as coming to the UK permanently on the day you return from your employment abroad and as resident and ordinarily resident from that date.

(Source: UK Inland Revenue).

Offshore Finance Guide Continued - Offshore Company