A minimum payment is the smallest amount that must be paid towards a credit card balance each month to keep the account in order. It is usually a small percentage of the balance plus interest and fees, or a set floor, whichever is greater.
In one line: A minimum payment is the least you can pay on a card each month, and paying only that makes clearing the balance slow and costly.
How a minimum payment works
Each statement sets a minimum payment, often calculated as roughly one percent of the balance plus that month's interest and charges, subject to a small fixed minimum such as 5 GBP or 25 GBP.
On a 2,000 GBP balance at 24.9 percent APR, paying only the minimum each month can take many years and add up to more in interest than the original balance, because most of the early payment covers interest.
Paying more than the minimum reduces the balance faster and cuts the total interest, since interest is charged on the amount still outstanding.
Common confusions
Paying the minimum keeps the account in good standing and avoids late fees, but it is not the same as paying the balance off and does not stop interest accruing on the rest.
Repeatedly paying only the minimum can lead to a persistent debt position, where the card provider must step in because more is being paid in interest and charges than in clearing the balance.
Primary source: FCA: credit card rules