Enkinho

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?