Credit card interest is quietly one of the most expensive forms of borrowing most people will ever use, and because it's billed monthly in small instalments, it's easy to lose sight of how much it actually costs over time. This guide breaks down exactly how UK credit card interest works, what minimum payments really cost you, and how to escape it faster.
The average UK credit card balance is £2,735. At today's average interest rate, paying only the minimum could take over 25 years to clear and cost more in interest than the original debt itself.
Credit card interest in the UK is calculated daily, not monthly, even though you only see it billed once a month. Your card provider takes your APR (annual percentage rate), divides it by 365 to get a daily rate, then applies that rate to your outstanding balance every single day. At the end of your statement period, all those daily charges are totalled and added to your balance.
This matters because it means your balance is compounding daily: every day you carry a balance, you're charged interest on the interest from previous days, not just the original amount you spent.
A £3,500 balance at 24.66% APR accrues roughly £2.36 in interest every single day it isn't paid off. That's nearly £72 a month in interest alone, before you've made a single payment toward the actual balance.
Credit card rates have risen sharply over the past decade. The average rate has climbed from around 17.6% a decade ago to over 24% today, and some sources tracking the full market average put it closer to 36%. Store cards and credit-builder cards tend to sit at the higher end, sometimes exceeding 40% APR for those with limited credit history.
Most UK credit cards set minimum payments at around 1-2.5% of your outstanding balance, with a typical floor of £25. This is where the real damage happens: because the minimum payment is a percentage of the balance, it shrinks as your balance shrinks. You end up paying less and less each month while interest keeps compounding on what's left, dramatically extending how long it takes to clear the debt.
A £2,735 balance at 24.66% APR, paying only the minimum (2.5% of balance, £25 floor), takes approximately 26 years to clear and costs around £9,133 in interest, more than three times the original balance.
The single most effective way to escape the minimum payment trap is to commit to a fixed payment amount rather than the shrinking minimum, and ideally increase it whenever you can.
| Payment Strategy | Time to Clear | Total Interest Paid |
|---|---|---|
| Minimum only (2.5%, £25 floor) | ~26 years | £9,133 |
| Fixed £100/month | 3.4 years | £1,324 |
| Fixed £150/month | 2.0 years | £727 |
The jump from minimum payments to a fixed £100/month cuts the payoff time from 26 years to under 4, and saves nearly £7,800 in interest. Going further to £150/month nearly halves the time again and the interest cost drops to under £730.
It's not really about how much extra you can afford each month. It's about breaking the cycle of a shrinking minimum payment. Even committing to a fixed payment equal to your current minimum, rather than letting it decrease as the balance falls, makes a significant difference.
A 0% balance transfer card lets you move existing credit card debt onto a new card with no interest for a promotional period, typically 12 to 30 months, in exchange for a one-off transfer fee usually between 1.5% and 3% of the amount moved.
This can be one of the most effective ways to reduce the cost of credit card debt, but only if you have a realistic plan to clear the balance within the promotional window. If the 0% period ends and a balance remains, it typically reverts to a standard rate similar to or higher than what you started with, undoing much of the benefit.
Making minimum payments on time does not directly hurt your credit score. It shows lenders you're meeting your obligations. However, carrying a high balance relative to your credit limit (known as credit utilisation) can lower your score even while you're paying on time, since it signals higher risk to future lenders. Paying down the balance faster improves both your finances and your credit profile simultaneously.
1. Pay more than the minimum, even slightly. Any fixed amount above the minimum dramatically cuts both the time and total interest, as shown above.
2. Stop the balance growing. If you're still spending on the card you're trying to pay off, new purchases accrue interest from day one and undo your progress. Consider separating everyday spending from any card you're paying down.
3. Target the highest rate first if you have multiple cards. This is the debt avalanche method: attacking the most expensive debt first minimises total interest paid across everything you owe.
4. Consider a 0% balance transfer if you can realistically clear it in time. This pauses the interest clock entirely, giving every payment a chance to reduce the actual balance rather than servicing interest.
5. Track the real numbers, not just the balance. Seeing exactly how much interest you're paying and how much an extra payment saves is often the motivation needed to commit to paying more than the minimum.
Finance Fortress is a free app that shows you exactly how much interest any debt is costing you, what happens if you overpay, and how long until you're debt free, calculated from your real balances and interest rates, not generic averages.
Add your credit card balance and see exactly how much an extra payment saves you in interest. Free, no bank connection required.
Try Finance Fortress Free →UK credit card interest is calculated daily by dividing your APR by 365 and applying that rate to your outstanding balance each day, with the total added to your balance at the end of the statement period.
As of late 2025/2026, the Bank of England puts the average rate at around 24.66%, while broader market averages tracked by Moneyfacts show closer to 36% when including all card types, with store and credit-builder cards typically charging the most.
If you're only paying the minimum, a large portion of your payment goes toward interest rather than the actual balance, especially early on. As the minimum payment shrinks with your balance, this effect can continue for decades on larger balances.
In almost all cases, paying off credit card debt should take priority over saving, since the interest rate you're paying (often 20-35%+) far exceeds what you'd realistically earn on savings. An exception is keeping a small emergency buffer to avoid relying on the card again for unexpected costs.
Applying for a balance transfer card typically involves a credit check, which can cause a small temporary dip. However, paying down debt faster as a result generally improves your credit profile over the following months.