Answers · UK 2025/26

How does a 0% balance transfer credit card work?

A 0% balance transfer card lets you move existing credit card debt onto a new card, paying no interest for a promotional period (commonly ranging from several months up to two years or more), giving you time to pay down the balance without interest accruing. Most cards charge a one-off transfer fee (typically 1-3% of the transferred amount), and the standard interest rate applies once the promotional period ends.

Last updated: 2 July 2026Last reviewed: 2 July 2026How we verify

Full answer

Balance transfer cards are a widely used tool for tackling existing credit card debt more efficiently, provided you understand the fee structure and have a realistic plan to clear the balance within the promotional period. **How the transfer works** You apply for a new balance transfer credit card and, if approved, request that some or all of your existing credit card debt be transferred to the new card -- the old card's balance is paid off (typically directly between the two card providers), and you now owe the transferred amount on the new card instead, benefiting from the 0% promotional interest rate for the specified period. **The typical transfer fee** Most 0% balance transfer cards charge a one-off fee, commonly 1-3% of the amount transferred, added to your new balance at the point of transfer -- this fee needs to be factored into your overall cost comparison, since a longer 0% period with a higher transfer fee is not automatically better than a shorter period with a lower fee, depending on how quickly you can realistically repay the balance. **Why the promotional period length matters** Cards are marketed with varying promotional period lengths, from around 6 months up to potentially 24-30+ months on the longest available offers -- generally, cards offering the longest 0% periods require a strong credit score to qualify for, and the specific rate/fee/length combination you are actually offered can depend on your individual credit profile, not just the headline advertised offer. **What happens after the promotional period ends** Once the 0% period expires, any remaining balance starts accruing interest at the card's standard rate, which is often significantly higher than typical average credit card rates -- if you have not cleared the balance by this point, the interest cost can escalate quickly, so having a clear repayment plan for the full promotional period is essential. **Worked example** Someone transfers £4,000 of existing credit card debt to a new card offering 0% for 24 months with a 3% transfer fee (£120, added to the balance, making the total owed £4,120). To clear this within the promotional period, they would need to pay roughly £171.67 a month for 24 months -- if they can manage this, they pay no interest at all (beyond the one-off transfer fee), a significant saving compared with paying down the same debt on a standard-rate card. **Common pitfalls to avoid** Missing a minimum payment can sometimes void the promotional 0% rate entirely under certain card terms, reverting the balance to the standard (much higher) interest rate immediately -- always ensure you can reliably make at least the minimum payment each month, and ideally set up a direct debit to avoid missing a payment accidentally. **Not a solution for new spending** A balance transfer card is designed to help pay off EXISTING debt -- using it for new spending in addition to the transferred balance (particularly if the card does not also offer 0% on purchases) can be a costly mistake, since new spending is often charged interest immediately, separate from the 0% balance transfer promotional rate. **Practical tip** Before applying, calculate the monthly payment needed to clear your transferred balance within the promotional period, and compare the total cost (transfer fee plus any expected residual interest) across a few different card offers, since the card with the longest headline 0% period is not always the cheapest option once fees are properly factored in.