By Lana Clements

American Express is tempting new credit card customers with an offer that's difficult to refuse. The provider has doubled the introductory cashback rate on its Platinum Cashback Credit Card from 2.5% to 5% for three months- the joint highest on the market.

Capital One also offers 5% for the same amount of time, and both cards cap cashback at £2,000 of spending with the three months, allowing customers to earn £100 during this time.

But after three months, the two cards' rates drop significantly. Capital One plummets to just 0.5%, allowing American Express to gain the edge by offering 1.25% on all purchases without a cap.

American Express also offers an annual month of double cashback at 2.5% on the cardholder's anniversary.

Also worth a look is Santander's 123 Cashback Credit Card, which pays a much higher ongoing 3% on petrol, although this is capped at £300 a month, and 2% on department store goods, as well as 1% on supermarket spending.

Those who are able to clear their balance each month, therefore avoiding interest charges, can make money or earn reward points with cashback credit cards. But in order to work out which cashback card will generate the best returns, shoppers should analyse their spending.

Julie Hay, head of credit cards at American Express, says: "The average family spends approximately £14,300 a year on everyday goods and services that could be purchased using a credit card.

"Rather than splitting this spending across debit and credit cards, people should think about consolidating as much of their everyday spending as possible onto a cashback card to maximise the payback they can earn."