An Oireachtas Committee will discuss whether PPS numbers can be used to update the electoral register later.
It has heard from witnesses that the absence of a unique identifier is causing problems for those trying to establish who is eligible to vote.
The Environment Committee will also consider whether responsibility for the 31 electoral registers should be transferred to the Electoral Commission.
Chairperson Michael McCarthy TD said that they will hear from the Data Protection Commission today, on whether PPS numbers can be used.
"In the absence of one unique identifier, such as the PPSN, it could cause huge difficulties in terms of having one uniform electoral register," he said.
"Now, there might be difficulties with that type of information because your PPSN is very unique, it's very sensitive information, and we would also want to ensure that in the context of delivery of public service, that that type of information would never end up in the wrong hands."