A spokesperson for the National Driver Licence Service has said its national system is now working properly after drivers were unable to renew their licences at 12 centres in the west and northwest this morning because of an IT problem.
The glitch hit the national service on its first day in public operation.
The spokesperson described the problem as a "teething" issue.
It came after a separate problem earlier when a phone-answering service in Cork left members of the public waiting for 20 minutes for service.
A spokesperson said the technical fault had occurred on lines to the customer service centre between 10am and midday.
Callers had been trying to get through to have queries dealt with about how the new national service will operate.
The NDLS said it is not in a position to calculate how many people were inconvenienced.
Callers to all 34 national centre offices were affected, but the NDLS said the issue has now been resolved.
The problem in trying to contact the new service was criticised by Seamus Boland of Rural Link community organisation.
He said members of the public and especially older people living in rural areas were depending on people answering the phones promptly as they could no longer go along to a local office to have their licence renewed.
"It's not as easy for rural people to access any more and that is not fair," he said.