I am thinking of renting out my place or a room in it - to help with bills and so on. My question is though, when it is rented out and I declare the income
How do you go about declaring it? And also, is the tax paid by me Monthly or in one lump at an End of Tax year type thing?
If you just rent out a room you may be exempt from tax on the income provided it meets the criteria of the "Rent-a-room" scheme.
If you vacate the premises and rent it out totally then normal rental rules apply.
In this case you would also be liable to register with PRTB and NPPR.
Registration is normally via form TR1 with Revenue and tax due is paid annually. However where net taxable rent is small yo may be able to continue filing via PAYE Form 12.