Start by deciding what you need the card for, such as purchases, balance transfers, building credit or rewards. Compare the interest rate, 0% period, balance-transfer fee, annual fee, rewards rules, late-payment charges and any introductory offer, rather than focusing only on the headline deal. Use an eligibility checker where available, as it can show likely options without a full credit application, although approval is not guaranteed. Check that the provider is authorised by the FCA and read the terms carefully before applying; the most suitable card depends on your circumstances and how you plan to repay.