I am renting out an apartment I purchased since March this year. It is my only form of income at the moment. I presume I will have to register for self-assessment. Do I need to pay preliminary tax in October this year? Thanks in advance!
Yes, you'll need to file a Form 11 for 2019 by 31st October 2020 (or slightly later with electronic filing). You won't have any preliminary tax to pay in October 2019 provided you didn't have any taxable income in 2019. Essentially taxable income is income that is not taxed at source and salaries/wages etc is the main source for this. PAYE is deducted on salaries etc so if you had any other taxable income then you may need to make a preliminary tax payment in October 2019. Become familiar with the 90% current year/100% prior year rules and the Revenue website covers this well.