Every UK credit card statement carries a box explaining what happens if only the minimum payment is made — it's a requirement under FCA rules, not something issuers include voluntarily. Most people glance past it. The numbers inside that box are usually the most important thing on the page.
How the minimum payment is actually set
There's no single fixed formula, but most UK card issuers use a version of the same structure: the minimum is whichever is larger out of a fixed floor, typically £25, or a percentage of the balance, commonly around 1%, plus that month's interest and any fees. Barclaycard, Halifax, MBNA and most others publish the exact formula in their terms and conditions rather than a headline percentage, because the figure moves depending on interest charged that month.
The practical effect: on a small balance, the £25 floor tends to apply, so a relatively larger share of each payment clears actual debt rather than interest. On a large balance, the percentage-based calculation takes over, and a much bigger share of the payment simply covers the interest that accrued that month, leaving comparatively little to reduce what's owed.
What it costs in practice
Take a card charging 24.9% APR — a fairly typical representative rate for a standard (non-0%) UK credit card in 2026 — with minimum payments set at 1% of the balance plus interest, subject to a £25 floor. Paying only the minimum every month:
- A £1,000 balance takes around 6 years and 3 months to clear, and costs roughly £942 in interest — nearly doubling the original debt.
- A £2,500 balance takes around 13 years and 11 months, and costs roughly £4,055 in interest — more than the original balance itself.
- A £5,000 balance takes around 19 years and 8 months, and costs roughly £9,242 in interest — almost double the amount originally borrowed.
These figures assume no new spending is added to the card and the interest rate never changes — both fairly generous assumptions, since promotional rates expire and most people don't stop using a card entirely while paying it down. Add any new purchases each month and the payoff timeline stretches further, sometimes indefinitely, because the minimum payment can end up barely covering the interest on the combined balance.
Why the balance can barely move for years
Early in the repayment period, interest eats most of the minimum payment. On the £5,000 example above, the first month's interest alone is roughly £104 (5,000 × 24.9% ÷ 12), against a minimum payment of around £154 — meaning only about £50 actually reduces the balance that month. As the balance slowly falls, less interest accrues and slightly more of each payment starts chipping away at the principal, which is why the final years of a long minimum-payment schedule move faster than the first years, even though the payment amount itself is falling too.
What changes the maths
A few factors shift these numbers meaningfully:
- APR. Cards range widely — some standard cards sit closer to 20%, others above 30% for people with thinner credit files. Every percentage point of APR adds months to the payoff time on any sizeable balance.
- Fixed versus percentage minimums. A card with a flat £25 minimum regardless of balance size clears faster on small balances but can barely dent a large one, since £25 might not even cover that month's interest once the balance passes a certain point.
- Any overpayment. Adding just £20 a month on top of the minimum on the £2,500 example above cuts the payoff time from around 13 years and 11 months to about 5 years and 10 months, and reduces the total interest paid from roughly £4,055 to around £1,777 — a saving of over £2,000, because extra payments go straight toward the balance rather than being partly absorbed by that month's interest.
Why several small cards add up faster than one big one
Someone with three cards each carrying a £1,000 balance at similar APRs, paying the minimum on each, ends up in a noticeably worse position than someone with a single £3,000 balance on one card. The reason is the £25 floor: three separate minimums each anchored near £25 to £30 means a bigger combined slice of the total monthly payment goes toward keeping three accounts technically serviced rather than toward reducing any one balance meaningfully. Consolidating balances onto a single card, or a personal loan with a fixed monthly payment and a defined end date, doesn't reduce the debt itself, but it removes the inefficiency of multiple floors working against the borrower at once — worth understanding as a mechanic even before deciding whether consolidation makes sense for a given situation.
The credit file angle
Making at least the minimum payment on time protects a credit file — missed or late minimum payments are reported to credit reference agencies (Experian, Equifax, TransUnion) and can knock a score down noticeably, in a way that's visible to other lenders for up to six years. Paying only the minimum, on the other hand, doesn't damage a score by itself — credit reports show whether payments were made on time, not whether more than the minimum was paid. What does affect scoring indirectly is credit utilisation: carrying a high balance relative to the card's limit for a long stretch, which a slow minimum-payment schedule almost guarantees, is factored into how lenders assess future applications.
When a 0% deal ends and the minimum stays the same
A common trap: someone transfers a balance onto a 0% purchase or balance transfer card, sets up a direct debit for the minimum payment, and stops thinking about it. If the balance isn't cleared before the promotional period ends, the account reverts to the card's standard APR — often 24.9% or higher — but the minimum payment formula doesn't change, so the minimum simply jumps to reflect interest that wasn't being charged before. A £2,000 balance that was comfortably managed at £25 a month during a 0% period can suddenly require £60 to £70 a month once standard interest kicks in, and the payoff clock effectively resets to the long timelines described above unless the balance is moved again or paid down faster. Calendar reminders set for a month or two before a 0% deal expires are one of the few genuinely useful habits here, simply because the change in minimum payment can otherwise arrive as a surprise on a statement rather than something planned for.
Where the minimum payment warning box comes from
The Consumer Credit (Agreements) Regulations require UK credit card statements to include an illustrative example, using the actual balance and APR on the account, showing roughly how long repayment would take and the total cost if only minimum payments are made. It's one of the few places on a statement where the numbers are calculated specifically for the individual balance rather than a generic example — worth reading in full rather than skipping to the payment due date, since the two figures next to each other, current balance and total cost at minimum payments, tend to be very different sizes.