Re: Oh, it's a new tax year here in the UK
"Last year was a bit more complicated - had to do a full tax return. Filled it in and submitted it online on HMRC's website; took about 20 minutes and cost £0."
I'm in the same boat as you now, because I let my house amongst other things.
I was determined to do it myself, however after spending a large part of a weekend tearing my hair out and not doing much for my already high blood pressure, I called an accountant to do it all for me.
Best £300 I ever spent, and I can claim 40% of that back next year.