Around 12,000 people will have made applications to the Residential Institutions Redress Board (RIRB) by the time the deadline for compensation claims expires at midnight tonight.
There had been calls on the Taoiseach to instruct the board to extend the deadline amid complaints that the impending cut-off for applications had not been sufficiently advertised.
The Aislinn group, which campaigns for victims of institutional abuse, said the Residential Institutions Redress Act (2002) provided for an extension of the deadline but the legislation only provides for this if the board is satisfied an application was late due to mental incapacity.
There has also been some controversy over institutions which were not covered by the RIRB. The State says they were not subject to inspections but campaigners say they were "feeder institutions" to larger homes covered by the board.
The RIRB was created to make awards to people who were abused as children at industrial schools, reformatories and other institutions subject to state regulation or inspection.
According to the its most recent bulletin in early November, a total of 9,551 applications had been received by that date. It also reported that the rate of application had increased to 600 per month and it is understood the rate has increased further. By tonight's deadline, around 12,000 people are expected to have applied.
The board has already compensated around 4,500 people. The average value of awards has been €76,500, with the largest award being €300,000.