Korea's income-contingent student loan (ICL) collects misunderstandings because of its name. Some borrowers assume repayment starts with the first payslip; others assume a little comes out no matter what they earn. In reality an obligation arises only in a year when you cross a threshold, and then only on the amount above it. The trouble is that the threshold appears as a different number every time you search for it. Start with why.

The foundation lends, the tax office collects

The first confusion is about which counter to use. The Korea Student Aid Foundation handles the loan itself and voluntary repayments, while the National Tax Service handles mandatory repayment once income appears. That is how you end up with no notification in the foundation's app and a notice from the tax office in the same month.

The contact points split the same way. Loan balance, grace period and voluntary repayment go to the Korea Student Aid Foundation (1599-2000); assessment of the mandatory amount, deferral and payroll withholding go to the National Tax Service (tax counselling centre 126) and the income-contingent repayment site (icl.go.kr). Asking the foundation about a deferral is a common way to lose several days.

The threshold is not salary, it is income amount

This is the crux. The repayment threshold is set on income amount, not gross salary. For an employee that means gross pay after the earned income deduction has been taken out.

The standard the tax office applied this year, for the 2025 income year, is an annual income amount of 18.98 million won, which converts for an employee to gross salary of 28.51 million won. These are not two different standards; they are the same line expressed two ways.

Checking the arithmetic makes it click. In the bracket around 28.51 million won the earned income deduction is 7.5 million won plus 15 percent of the amount above 15 million won, roughly 9.52 million won, and subtracting that from 28.51 million leaves about 18.98 million won. The two figures line up exactly.

Why a search returns several numbers

Look up the repayment threshold and conflicting amounts appear side by side. There are only two causes.

• The basis differs — some articles quote income amount, others quote the gross-salary conversion
• The income year differs — the figure is reset by notice each year. For the 2024 income year it was an income amount of 17.52 million won, or 26.79 million won of gross salary

So any page that merely copied a number ages badly. When you check, look for which income year it refers to and whether it is income amount or gross salary. Material that states neither is not worth trusting.

The obligation attaches only to the excess

Crossing the line does not mean repaying the whole balance. The formula runs as follows.

An undergraduate borrower whose income amount exceeds the line by 2 million won therefore starts from 400,000 won, being 20 percent of that excess. From there, anything repaid voluntarily to the foundation last year is deducted. Money paid early does not evaporate, which is an argument for putting small amounts in when you can.

There is one route to an obligation without a salary: property received by inheritance or gift. That can apply even before employment, so it is worth checking separately.

April notice, prepay by end of June, then withholding

Knowing the calendar is what gives you options. Once the April notice arrives the path forks.

• Prepayment — pay all or half directly. Prepaying by the end of June takes you out of payroll withholding
• Withholding — if you do not prepay, your employer deducts one twelfth of the amount each month for a year

The difference is not the total but whether your employer sees it, and what it does to monthly cash flow. Withholding is collected through the company, so it appears as a line on the payslip. If that is uncomfortable, or if you can put down a lump sum, the end of June becomes the date that matters.

If repaying is hard: two years, or four while studying

Some people receive the notice and cannot pay it. That is what deferral is for, and the length depends on the ground.

• Job loss, resignation or parental leave and similar financial hardship — two years
• Enrolled at a university or graduate school — four years

The paperwork differs by ground. Job loss or resignation needs proof such as a certificate of separation; parental leave needs the personnel order together with a family relation certificate showing a child in your care. Apply and check the outcome at icl.go.kr; the result also arrives by written notice from the district tax office.

Deferral is not forgiveness. The postponed amount is charged again once the deferral ends. The interest burden is not structured to snowball, since the 2026 student loan rate has been held at 1.7 percent for a sixth consecutive year, but the fact that it returns as a lump has to be built into the plan.

The order to work in

• 1. Confirm whether your loan is standard repayment or income-contingent — this article does not apply to the other type
• 2. Check whether an April notice from the tax office arrived, at icl.go.kr rather than in the foundation app
• 3. Check whether the notice states income amount or gross salary, and which income year
• 4. Check that voluntary repayments were deducted from the excess times 20 percent, or 25 for graduate loans
• 5. Decide between prepaying and leaving it to withholding — the end of June is the dividing line
• 6. If you are out of work, on parental leave or studying, prepare a deferral application and its proofs

If you are still at the borrowing stage, start with the difference between standard and income-contingent repayment, and to reduce the tuition bill itself the entry point is how recognised income is assessed for national scholarships. Support at primary and secondary level is covered separately in education benefit and education cost support.

This article draws on National Tax Service guidance on income-contingent student loan repayment and government policy briefing releases, Korea Student Aid Foundation loan guidance including the 2026 rate of 1.7 percent, and notices on the income-contingent repayment site (icl.go.kr), as confirmed in August 2026. The repayment threshold is reset by notice each year and the applicable amount differs by income year. Check your own assessed amount and deferral eligibility directly at icl.go.kr, and if the position is unclear, confirm it with the tax counselling centre (126) or the Korea Student Aid Foundation (1599-2000).