You’ll get a Personal Allowance of tax-free UK income each year if any of the following apply:
you hold a British passport
you’re a citizen of a European Economic Area (EEA) country
you’ve worked for the UK government at any time during that tax year
You might also get it if it’s included in the double-taxation agreement between the UK and the country you live in.
Claim the Personal Allowance
If you’re not a UK resident, you have to claim the Personal Allowance at the end of each tax year in which you have UK income. Send form R43 to HM Revenue and Customs (HMRC).