0% purchase credit cards work by not charging interest on spending made using the card during the pre-defined interest-free period. It is possible to spend up to a pre-set credit limit, which might be a few hundred pounds or may be several thousands of pounds, depending on your individual situation.
At the end of the introductory interest-free period, interest will then start to be charged on the amount borrowed at the provider's standard purchase rate. For this reason, it is best to try and pay off as much of the balance as possible before the interest-free period ends.
At the very least, a minimum payment – as set out by the provider – must be paid each month, even during the interest-free period. Setting up a standing order or a direct debit is the best way to make sure minimum payments are always paid. If a minimum payment is missed, a penalty fee may be charged, the interest-free period may be withdrawn, and your credit rating could also be adversely affected.
Given the need to try and clear the borrowing before the introductory period ends, and so avoid paying the standard purchase rate, it makes sense to pay more than the minimum payment if you can. Indeed, when spending using a 0% purchase credit card, it is sensible to have in mind your own personal 'credit limit', that you think you will be able to repay within the introductory period and make your own repayment plan. One option is to divide the total balance owed by the number of interest-free months the card offers, giving you an evenly split amount to pay off each month. Alternatively, it may be the case that you only want to make the minimum payment each month, and then save up enough to pay off the rest just before the interest-free period ends.
Once the interest-free period does come to an end, interest will start to be charged on any outstanding balances and on any further purchases. At this point, it may be sensible to transfer an outstanding balance to a 0% balance transfer credit card, giving you more time to pay off the debt interest-free. If you plan to carry on spending, it will probably be best to look for another 0% purchase credit card.