If you are moving abroad for an extended period, then you can arrange your affairs to minimise tax.
For example, if you are planning to move, say, to Central America for two or three years, then it is possible to elect not to pay UK income tax but, rather, to pay tax in the other country.
If the income tax in the country you are moving to is lower than UK tax then you will be at an advantage.
There are many possibilities available to you when you are British, but resident outside Britain.
We would need to discuss your exact plans with you so we can advise on the best course of action in your case.