Under the scheme, known as tier pricing, Citibank will offer from April 1 annual rates of 18 per cent on rollover credit for its most creditworthy clients - below the industry average of 24 per cent.

A Citibank spokesman declined to give more details, but the scheme will apply to Citibank Gold and Platinum cards initially.

Customers are evaluated on a number of factors, including how long a customer has been a cardmember, usage and payment behaviour, the bank said.

If the customer, however, fails to pay at least the minimum sum required by the due date twice or more within six months, then the interest rate could go as high as 27 per cent a year.

An account is considered past due if the minimum payment due is not received in full before the payment due date.

This rate will revert to the usual 24 per cent a year once a customer's account is no longer twice or more past due in the last six months, it said.

'We want to be able to reward customers who have shown good payment behaviour over a period of time with a promotional lower interest rate,' said Radha Suvarna, director of portfolio management and cross-sell, Citibank Singapore.

'The implementation of tiered pricing based on payment behaviour seeks to encourage all customers to adopt good payment practices and be rewarded for it.'

From the standpoint of a consumer, in particular a creditworthy one, using credit cards that offer different interest rates depending on spending behaviour and risk profile, or risk-based pricing in short, can be beneficial.

For one, a customer could save on interest charges.

Read the full report in Thursday's edition of The Straits Times.