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0% on purchases cards are the best way to delay the cost of purchases. Here are the top cards, plus some tips on avoiding the nastier small print.

Each credit card has its purpose. Using it in the wrong way will typically be very costly. But what is the right way?

If you want to space out the cost of big or multiple purchases, the best card for you is a 0% on purchases card. You pay no interest for an agreed period and, unlike balance transfer cards, you don't pay a fee either.

Here are the top five 0% on purchases cards available in the whole market:

Top five 0% on purchases cards

Tesco's is the longest at 12 months, which is a long time to space out payments for purchases. It's also offering double Clubcard points this summer for purchases you make abroad, although that deal expires on 30 September, so you might not have many weeks once your card arrives. It may also be a very expensive way to buy abroad.

These cards do the usual trick of reverting to a very high rate (typically 16% to 18% APR) after the deals expire, so pay off the cards before then! There is one exception, which is Saga. That 'typically' charges 12% APR which, although lower, is still high; there are cheaper ways to borrow.

How do the card providers make money?

As there are no fees or interest, it's sensible to ask how these cards make the lender money.

The obvious answer is they hope you over-spend and can't pay your card off on time, or that you'll continue to use it after the deal ends. Alternatively, they hope you'll buy their very expensive insurance to go with it. (It's ten times cheaper - no kidding - to search the internet for an independent payment protection insurer and buy it separately. The cover is usually better too.)

The less obvious answer is they hope you won't understand their terms and conditions correctly and you'll mess up. That's what they really want. The main three ways to slip up are:

• Missing a payment. This will mean a penalty charge and, worse, the immediate end of your 0% deal. You must pay off the minimum amount every month, even while interest is not being charged.
• Buying extras, such as travel insurance or travel money. However, these extras are never at a good price, or even close.
• Using your card for anything other than making a purchase (e.g. for a balance transfer, to withdraw cash or to gamble). This will end up being extremely expensive for you, because it will land you straight into a trap called negative payment hierarchy. Read Don't fall for this card trick to find out more.

Go for better terms and conditions

There are exceptions to that last bullet point.

Nationwide and Saga have different rules that mean it's quite safe to use your card for both balance transfers and purchases. These organisations often have much fairer terms and conditions than any other lender, and that certainly is true for their credit cards. Nationwide's purchases deal is just three months though, at present. Saga is offering 0% on both purchases and balance transfers for nine months, with a 3% fee on balance transfers. A 3% fee is standard these days. Both cards have excellent terms and conditions, so check them out.

Other exceptions are Halifax and Bank of Scotland (of the Lloyds Banking Group) which, like Saga, have the unusual offer of a nine month 0% deal on both main sections: transfers and purchases. Just like most balance transfer cards, you have to do the transfers within 90 days. The transfer fee is 3%.

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