If I am not resident and not ordinarily resident in the UK for UK tax purposes, do I still have to pay UK tax?

The duties of UK Crown servants are treated as being performed in the UK regardless of where in the world they are carried out. Therefore, the salaries of Crown Servants remain chargeable to tax in the UK in accordance with UK tax legislation.

If you are treated as not resident in the UK for tax purposes, you can claim the UK tax personal allowances against income liable to tax in the UK.

More information can be found in the notes accompanying form R43.

Details of the current level of allowances and rates of tax can be found here.