The Department of Education says a new portal for Leaving Certificate students to register to receive calculated grades has been stress tested, to make sure it doesn't crash.
Some 61,000 students are expected to register on the portal from 10.00am on Tuesday.
The system will remain open for registrations until 10.00pm on Thursday.
All Leaving Certificate and Leaving Certificate Applied students are required to register.
And all those following the Leaving Certificate Established or Leaving Certificate Vocational Programmes are also required to confirm the level at which they intended to sit each of their subjects.
Students will also have to confirm the level of exam they would have sat, or they can change to a lower level.
Andrea Feeney is the director of the executive officer at the Department of Education.
She explained the process to Newstalk Breakfast.
"This is a brand new service that we've put in place to support the delivery of calculated grades for Leaving Certificate students this year.
"And before they start they'll need four pieces of information: their PPS number, their examination number, an e-mail address and their mobile phone number.
"And what we're asking them to do right now is to register for the service".
Describing the portal as a "one-stop shop" for calculated grades, she said: "At this point in time we need them to register.
"And if they're following the Established Leaving Cert or the Vocational programme, they also need to confirm their subject levels
"Ultimately they'll get the opportunity to opt in to receive calculated grades, and when we issue the results of the calculated grades they'll be issued through the portal as well".
However the subjects they will be taking will already be pre-populated in the system.
"Students might have entered initially at a higher level, but changed to a lower level in school and have been following that level in school.
"So we need them to go in now and confirm that that's the level that they actually had intended to take the examination at, that that's the level that they've been following in the school, so that we can have the most up-to date-information.
"When this part of the process is complete - so after Thursday when the portal closes - we'll provide that information to schools so that the schools can provide an estimated percentage mark and a ranking of each of their students."
On any aspect of the system being overwhelmed, she said: "We've done a lot of stress testing and we've been working with our internet service providers to make sure that that doesn't happen".
While Education Minister Joe McHugh said: "Every school has been sent on the information to provide to their students so that they are able to complete the registration on the student portal.
"This is a brand-new system that it has been necessary to introduce because of the decisions we have had to take as we respond to COVID-19 situation."
"The important message for Leaving Certificate students is that they must now register by Thursday at 10.00pm to ensure that they can receive their Leaving Certificate calculated grades.
"It is also essential that students confirm their levels at this time so that schools can complete the task of providing information for each student about their expected level of performance in each subject.”
Schools have been asked to assist their students as much as possible but if anyone has trouble getting access online, there will be helpline support from midday on Tuesday.
Minister McHugh added: "Please don’t leave it until the last minute. This is a tight timeframe.
"We need every student to register so that the new system can operate smoothly."