Most people work out the cost of a mid-year retake by starting with academy fees. But the variable that makes the biggest difference to the amount lies elsewhere: when you take the leave of absence. A few days either way can preserve or destroy a full semester's tuition.

The lines that decide the money: "start of semester" and "course-change deadline"

Tuition refunds are framed by the Rules on University Tuition Fees. The key is the reference date.

If the grounds for a refund arise up to the day before the semester begins, an enrolled student recovers the full tuition fee already paid. For a new entrant, up to the day before enrolment the whole amount including other charges is refunded.

If the grounds arise after the semester has begun, the position changes. The admission fee and other charges are not refunded. Only part of the tuition fee is returned, under each university's rules — generally a structure in which the refund proportion falls the further into the semester you are.

A leave of absence has its own buffer. Where a student takes leave in a semester for which tuition has been paid, the full tuition fee is refunded from the start of the semester up to the day before the course-change deadline. In other words, confirming the leave within a few days of the semester starting can protect that semester's tuition.

The trap most people miss — the reference date when withdrawing while on leave

The route a mid-year retaker typically takes is this: attend the first semester, take leave, sit the CSAT, and withdraw from the original university if successful.

This is where the misunderstanding arises. People assume, "I withdrew in the winter, so it will be calculated from then". The rules say the opposite. Where a student withdraws while on leave, the date on which the grounds arose is the date the leave began, not the date of withdrawal. And where tuition has been paid and leave and return have alternated, the reference is the date of leave in the semester during which the student's status was "enrolled" for the longest period.

So what actually has to be checked is not the date of withdrawal but when the leave of absence was submitted and confirmed.

Items people leave out of the calculation

The total cost of a mid-year retake is not academy fees alone. In practice the following move together.

• Unrecoverable tuition — arises when the reference dates above are missed. Often the single largest loss in a mid-year retake.
• Admission fee and other charges — not refunded after the semester begins.
• National scholarship treatment — taking leave or withdrawing may trigger repayment of scholarship money already paid. Check with the university's scholarship office.
• Dormitory fees, student union fees and so on — governed by separate rules.

The question of when to settle your enrolment status

After a successful application you have to settle your status at the original university. The principle is not to be enrolled at two universities at once, and the procedure and deadlines differ under each university's regulations. Because the period between results and enrolment at the new university is short, failing to check the procedure in advance leads to rushing paperwork and missing deadlines.

The checklist before deciding is as follows: your university's permitted timing and maximum duration of leave, the course-change deadline, the tuition refund table, and the withdrawal procedure and how long it takes. All four are published in the academic calendar and the university regulations.

On the decision itself

This article neither encourages nor discourages a mid-year retake. But the basis for the decision should be numbers rather than feelings. Writing down the tuition you can recover, the additional costs, and the preparation time left and comparing them makes the decision much quicker. Managing study during a second attempt is taken up in University Admissions.

In summary

What drives the cost of a mid-year retake is not the choice of academy but the reference dates: the day before the semester begins, the day before the course-change deadline, and the date the leave is processed. Check those three in your university's academic calendar first. Looking at academies after that is not too late.