You will need to read the guidance at RDR1 Residence, domicile and the remittance basis: RDR1
and then apply the tests which can be found at RDR3 RDR3 Statutory Residence Test
Once you have determined your residency status and if split year treatment applies, you can then look at your domicile and lastly, whether the remittance basis is appropriate.
If split year treatment applies, then you will need to register for self assessment at Register for Self Assessment
You can download and print off the tax returns (SA100) and Residenc supplementary page (SA109), along with any other relevant supplementary pages at
Self Assessment tax return forms
If you need to declare your foreign earnings on SA106, you will need to convert your earning to pounds sterling.
To convert from a foreign currency to pounds sterling, please use the official rate of exchange at the time of the exchange.
You are free to use the yearly rate, the monthly rate or the spot rate.
If a conversion was undertaken to deposit the money into a UK bank account, then this figure can be used.
The supplementary page SA106 must be completed using pounds sterling only.
The official exchange rates can be found at Exchange rates from HMRC in CSV and XML format
SA106 supplementary page
SA106 Completion notes