Why Your Credit Card Balance Barely Moves (UK)

You pay £39 and the balance drops by £14. The other £25 went to the lender before you touched a penny of what you borrowed.

One month, taken apart

Our own illustration, not a quote. We took £1,415, the average credit card debt per adult in May 2026 according to The Money Charity (The Money Charity), and the 21.45% effective rate it reports for interest-charging cards in the same month. We assumed a monthly rate of one twelfth of that, and a minimum payment of interest plus 1% of the balance, with a £25 floor. MBNA says its minimum is the greater of £25 or interest, fees and a percentage of your balance, without giving the percentage (MBNA), so your card will differ.

• Interest for the month: £25.29 (about £0.83 a day).
• Minimum payment: £39.44.
• Left over to reduce the borrowing: £14.15.

Three ways to pay the same card

On the minimum, the interest alone is more than the £1,415 you borrowed. The fixed £100 costs less in total interest than the minimum costs in its first year and a half. Add a new purchase and every figure here gets worse.

When your provider writes to you

On our assumptions, the first 18 months of minimum payments would put £234 against the borrowing and £419 into interest. That is the pattern the FCA’s persistent debt rules are aimed at (FCA PS18/4). If a letter like that arrives, it is a prompt to pay more or ask for help, not proof that you have done something wrong.

What people usually ask next

Why does my balance barely move when I pay every month?

Most of a minimum payment can be interest. In our illustration a £1,415 balance costs about £25.29 in interest in the first month, so a £39.44 payment takes only £14.15 off what you borrowed.

What is the ‘persistent debt’ letter my card company sent?

FCA rules say firms must check at least monthly whether your payments over 18 months were mainly interest, fees and charges rather than the money you borrowed. If so they must write to you, explain that higher payments would cut your costs, and give not-for-profit debt advice contacts (FCA PS18/4). The rule does not apply if your balance was below £200 at any point in the 18 months.

Can my card really be cancelled for this?

The FCA’s rules say that if payments are still mainly interest, fees and charges after another 18 months, the firm must offer ways to repay faster and, if you do not respond or will not pay what you can afford, suspend or cancel the card. If you cannot afford the options, the firm must give forbearance, which means giving you time and support (FCA PS18/4). Free help: StepChange on 0800 138 1111.

Is it better to pay a fixed amount than the minimum?

In our illustration, £100 a month clears the £1,415 in 17 months for about £231 of interest, while the minimum takes 104 months. A fixed amount does not shrink as your balance falls, which is why it works. Our minimum payment trap calculator runs your own numbers.

Does the interest grow every day?

Our daily compounding guide goes through how interest is added and what we could and could not verify.

Can I stop paying and let it sit?

MBNA says a missed payment can lead to a late payment charge and can affect your credit rating (MBNA). See our what happens if you stop paying guide before you try it.

What if I cannot afford more than the minimum?

Talk to your provider early and to a free adviser. StepChange offers free, impartial debt advice on 0800 138 1111 (StepChange). A 0% balance transfer or a consolidation loan can lower the interest, and our comparison guide shows the trade-offs.

Worth reading next

• APR vs Interest Rate (UK): The Real Difference
• Debt Management Plan UK: How It Works and What It Costs
• How to Improve Your Credit Score Fast in the UK (2026 Guide)
• Should You Save Money or Pay Off Debt First? (UK)