Tens of thousands of students are expected to register on the CAO website before this evening's deadline.
Initial applications need to be in before 5.15pm, but a change of mind form can be submitted up until July.
Up to 75,000 people went through the Central Applications Office last year and it is believed even more may apply this time.
Points for many third-level courses are expected to go up, with construction, engineering and business proving more popular as the economy improves.