Credit cards: grace period and the minimum-payment trap

A credit card costs nothing — as long as you use it a particular way. The key is the grace period: purchases repaid in full by the end of it carry no interest. In Ukraine it's often around two months as of 2026, but every card sets its own rules.

So a card stays free when every purchase is cleared in full within that window. An automatic full repayment on payday makes it reliable, and using the card only for things the account could already pay for keeps you from carrying a balance you can't clear.

Two habits break it. Cash withdrawals and transfers are usually charged interest from day one, often with a fee, and the grace period doesn't cover them. And paying only the minimum leaves a balance behind, which starts earning interest the moment the grace period ends. Free is all-or-nothing: part-payment isn't part-free.

Interest on a card is simply the balance times the monthly rate, so you can read it backwards: balance = interest ÷ rate. If Sam was charged 1,480 at 3.2% a month, the balance behind it was 1,480 / 0.032 = 46,250 UAH.

That also shows what his payment really did. Sam paid exactly 1,480 that month — the whole of the interest and not a hryvnia more — so the debt didn't fall at all. Then September's 6,558 gap landed on top, taking the balance to about 52,800 by November.

The lesson: a payment equal to the month's interest holds the debt perfectly still. To make a balance shrink, the payment has to be larger than the interest; everything above the interest is the only part that touches the debt itself.

When the minimum payment equals the month's interest, a year of payments buys nothing but another year of the same debt. Sam's 52,800 at 3.2% a month costs 52,800 × 0.032 = 1,689.60 of interest each month. Pay only that, spend nothing new, and after twelve months 12 × 1,689.60 = 20,275.20 UAH has gone — and the balance is still 52,800.

That 20,275.20 is the price of simply keeping the debt for a year, a little under 40% of the whole balance. Next year it repeats, and the year after.

Paying the minimum on time keeps the credit record clean, which is why it feels responsible, but it does nothing to the debt. Seeing the yearly interest as a number — over twenty thousand hryvnias for no progress — is often what makes a fixed, larger payment feel worth it.

A fixed payment above the minimum is what actually clears a card, and raising it saves interest twice over: fewer months, and a faster-shrinking balance to charge interest on. Because the interest falls every month while the payment stays the same, a growing share of each payment hits the debt itself.

For Sam's 52,800: paying 3,000 a month clears it in 27 months with 26,096.96 of interest; paying 4,500 clears it in 15 months with 14,456.60. The bigger payment saves 26,096.96 − 14,456.60 = 11,640.36 UAH and ends the debt a year sooner.

The extra 1,500 a month isn't lost — it goes straight into the principal, shrinking the base that interest is charged on, which is why the saving is far more than 1,500 × the months. Within what the budget allows, the largest fixed payment is the cheapest.

A minimum payment is designed to be easy, not to clear the debt. On Sam's card it's 3% of the balance but never less than the month's interest, and at 3.2% a month the interest always wins. So the minimum is just the interest: 52,800 × 0.032 = 1,689.60.

Pay exactly that and nothing new, and the maths is stark: 1,689.60 of interest is added and the same 1,689.60 is paid, so the balance never moves. A year later it's still 52,800, after 20,275.20 paid. Even a card with a 5% minimum would stretch the debt over about 14 years and roughly 135,000 paid, because the minimum shrinks as the balance shrinks, so the debt never takes a real hit.

Paying the minimum on time protects your credit record, which is worth doing — but it is not the same as paying the debt down. Only a fixed amount above the minimum does that.