Self Assessment / P85

I have just got to the final page of P85 where it asks if I would like to claim repayment now. What is the guidance if I will very soon be completing Self Assessment for relevant tax year. Claim via P85 or Self Assessment? Also will this be aligned with the double taxation Spain agreement i.e what is refunded I then declare for tax in Spain?

Hi ,
 

As you need to complete a Self Assessment return for the relevant tax year, you should claim any repayment due via your return. Sorry, can't comment on what might be required by the Spanish Tax Authorities, but the UK/Spain DTA should clarify any double taxation-related issues.            See  :   Double Taxation Relief Manual  . Thank you .