STUDENTS still waiting for grant approval face being shut out of essential college services such as libraries and computers.
The delay in approving and paying out grants may also be contributing to a rise in demand for financial help from college hardship funds.
About 50,000 students, mainly first years, are still waiting to hear whether their grant has been approved after a new online system introduced in June was beset by delays.
The chaos is affecting students who have to pay an annual charge of €2,250 to register with the college and avail of all services like computer and library access.
Students in receipt of a grant are exempt from paying the charge, but to do this they must show they have grant approval and that the money is on its way.
If they cannot show this, they may be asked to pay the charge upfront and seek reimbursement once the grant has been paid.
Union of Students in Ireland (USI) vice president Cat O'Driscoll said the processing delay had caused confusion in relation to access to services, such as libraries.
Ms O'Driscoll said colleges had been accommodating where students had explained the difficulty, but she felt some students may not have come forward.
City of Dublin Vocational Education Committee (CDVEC), which is operating the new online system known as SUSI, claimed that applicants were mainly to blame for the delays.
It said that hard copy documents to be provided in support of the online application process were not always being sent in.
But a number of parents outlined to the Irish Independent the problems their children had encountered with SUSI.
One student, who spent the first year of his life in the UK, was asked to provide fifth year school reports as evidence of living in Ireland, even though he had submitted both his Junior and Leaving Certificates.
Another mother told the Irish Independent that her son applied to SUSI in July and received an acknowledgement in August, and nothing more until he received a final warning letter earlier this month.
The letter said his application would be withdrawn unless he submitted all documentation as itemised in the documentation pack.
"We said we never had any communication from them and asked where could we download the documentation pack," she said after searching their website.
"We received a reply 10 days later to say, 'Sorry, our mistake; we have to send you the documentation pack'," she said.