The Crew, actually that's not correct, the amount of UK tax you will pay depends on your country of residence, if a DTA exists and how the UK see your tax status:
https://www.gov.uk/tax-uk-income-live-abroad/overview
You will normally always be stopped your NI in the UK as this is paid by the employer and the employee, social security benefits can usually be transferred to your country of residence.
In the UK if you are a " tax payer" the UK HMRC will give you a tax code which allows for a tax free amount. If you are non resident you will not get this allowance.
https://www.gov.uk/tax-uk-income-liv...ad/taxed-twice
You can contact the UK HMRC helpline, as for the " non-resident" section and they will clear the fog.. +44 135 535 9022