Double taxation

I come and go between Portugal and the uk during the year, working around 100 days in a tax year in the uk, it being my only income. I end up spending most of my time in portugal (230days plus). I have a home in portugal and I rent a room all year round in the uk. From what I gather I am a dual resident. I'm due to be taxed in portugal and I will be submitting a HS302 form together with the resident, remittance, etc form, but I need the UTR, which I tried to register for but i just received an email saying it doesn't match their records? What am I doing wrong? Also the tax year in portugal is from 1st January till 31st December, do I consider the uk tax year April to April as January to December?

Hi,

Some of your details may be out of date from what is held on our records so that they no longer match up to date information. you will need to contact our Income Tax team to ensure everything is up to date. you will still consider the UK tax year as 06 April to 05 April.

Income Tax: general enquiries

Thank you.