Dublin City Council has admitted that some voter registration forms "went astray" following an "unprecedented" surge in applications.
Almost 20,000 names were added to the supplement to the register in the Dublin City Council area alone.
The supplementary register covers those eligible to vote for the first time and those who are switching their vote from one address to another.
All of these applications were received by the close of business on May 8th, the last date for applying to join the register in advance of the referendum on the Eighth Amendment.
In a statement, Dublin City Council said two local authorities have to be involved in the process of a voter switching from one area to another.
The statement added: “Due to the volumes and tight timeframes a few forms went astray. Dublin City Council has made every effort to facilitate voters over the last few days who find themselves in this situation.
"If voters have not received a polling card they should confirm tonight they are on the register by going to checktheregister.ie."
Dublin City Council did not state how many voter registrations had gone astray.
The council also advised voters who had submitted their forms late or whose forms had not been processed to check the register for their local authority area as they may still be on it.
Dun Laoghaire Rathdown County Council said it too had received an "unprecedented" number of applications for inclusion on the supplementary register.
The council said that all valid applications received before the deadline were processed and none were omitted from the register.
More than 118,000 people have been added to the supplementary voter register for the referendum, according to the Department of Housing, Planning and Local Government.
This is more than twice the 65,911 who were added to the supplementary register for the marriage equality referendum.
As a consequence, 3.2 million people are now registered to vote in the abortion referendum.
The Minister with responsibility for the electoral process has denied suggestions by the prominent No campaigner and independent TD Mattie McGrath that there are “irregularities” with the electoral register.
Mr McGrath claimed some people had been put on the register without their knowledge. He also asked if “international observers” would monitor the referendum process.
Eoghan Murphy, the Minister for Local Government, said some campaigners could be attempting to undermine the referendum result by questioning the referendum process.
Speaking to The Irish Times, Mr Murphy said: "We have a very robust electoral process in this country. And I'd be worried that some people on the No side might be trying to undermine the integrity of the outcome by questioning that process and by questioning the procedure by which people get on the register of electors and go out and actually exercise their right and go and vote."
