Ah I love it, your friend has you flapping around while they remain blissfully ignorant of their own responsibilities! Seen it so many times...! First things first, is the net rental income (rent receivable minus allowable interest and expenses) greater than €3,174 in 2011? If no, then your friend doesn't need to register for income tax self-assessment or for ROS, bt just needs to complete a Form 12 for 2011, and he'll get a balancing statement in due course telling how much, if anything, he owes. If yes, then your friend is possibly goosed, as it could take weeks to get registered for income tax via TR1 and then register for ROS, given that it's now the busiest time of year. But anyway the process would be: Complete a form TR1 (to notify the tax office that he needs to be registered as a self assessed taxpayer). Once he has his registration for income tax confirmed, he then can register for ROS to file his return online and pay his tax by DD mandate / Laser. If he can get 1 & 2 above sorted before 15 November, he can just scrape the extended deadline for filing and paying online.