Just read the oireachtas committee discussion on the big discrepancy between the CSO number of people renting from private landlords and the much lower number registered with the RTB.
The methods used to record Student and AHB's with RTB was mentioned as possible explainations for some small differences as well as properties being let to family which are not registered, but the clear implication was that tens of thousands of landlords had broken the law and not registered. What about the large numbers of refugees who are renting from private landlords on the €800 pm plan? Would that skew the figures as they are not required to register with RTB either.
I would have thought the vast majority of landlords are registered now but maybe not. The CSO are to carry out a matching exercise between rtb, cso, and lpt data to identify where the discrepancies are so it will discover if there really are thousands of dodgy landlords. The results from the CSO exercise will be interesting.