Customers who store credit card numbers and shipping addresses with Amazon can choose to have that information represented by a "PayPhrase" and PIN. When making a purchase, they enter their own customised phrase - such as 'Knick Knack', 'Home Sweet Home', or 'Jake's Allowance' - and PIN and are shown an order confirmation before checking out.

Amazon says the system is easy and secure because shoppers do not need to sign in with usernames and passwords or enter their payment information. Customers can adopt multiple PayPhrases to map against multiple shipping instructions and card accounts.

The system also works with Web sites that accept Checkout by Amazon - including DKNY, Jockey, Patagonia and Buy.com - cutting back the number of passwords customers need to remember and the amount of companies they hand over card details to.

Matt Williams, general manager, Amazon PayPhrase, says: "PayPhrase solves the headache of trying to keep track of all the different usernames and passwords people use to shop on various sites across the web. With PayPhrase all you need is one phrase and one PIN to pay online. We think customers will enjoy the simplicity that Amazon PayPhrase offers, and we hope they'll have some fun choosing their own personal phrases."

Amazon says the system also makes it easy for parents to set up an online allowance and monitor their teens' purchases, or for small business managers to maintain control over corporate cards. Users can set monthly spending limits and monitor or approve purchases for particular cards. They can preview every order placed and approve or decline each order via e-mail or mobile phone text alerts.