Major card players show their hands

Million of credit card customers will have the intimate details of their accounts shared by banks following an agreement announced last week by four major card companies.

Lenders already share limited information about customers' credit details, including missed payments, unauthorised spending, how much they owe and whether payments are up to date. But now Barclaycard, the Co-operative Bank, Egg and Abbey have agreed to reveal more detailed data to help identify customers who are getting themselves into financial difficulty.

The information will be supplied through the main UK credit reference agencies, Experian, Equifax and CallCredit. It will go to any credit card issuer providing the same information about its customers and will include how much you spend each month and how much you pay off your credit card balance.

However, Barclaycard is unlikely to be able to provide this information before the second quarter of next year, so excessive use of your plastic over this Christmas should not show up.

Ian Barber, a spokesman for Barclaycard, says that the move is in response to a commitment to greater data sharing made by Barclays chief executive John Varley to the Treasury Select Committee a year ago.

'This information will enable us to make better decisions about those customers who are vulnerable, who are already overextended,' he says.

Barclaycard says borrowers who are not stretched by their credit should be unaffected by this move, and may be offered further credit. But those who are paying off only the minimum each month, or have missed a payment, may find credit applications refused and even have their current credit limits reduced.

However, rather than leaving such people in limbo, the banks may advise them to seek help from organisations such as the Citizens Advice Bureaux or the Consumer Credit Counselling Service (CCCS) or, in the case of existing customers, help them to set up payment plans and restructure debt.

Barber says that the information could not be shared with other parts of the banks or used for marketing purposes.

The CCCS welcomes the move to share more information about borrowing. Spokeswoman Frances Walker says: 'We've seen an awful lot of extreme debt cases where people have been able to build up huge amounts of credit by paying off the minimum every month.

'In one recent case, a professional' cellist, who worked on a freelance basis with an orchestra, built up debts of £58,000 that he could not cope with because of the ebbs and flows in his income. He has gone bankrupt.'

The CCCS has received more than 200,000 calls this year from people seeking advice on handling their debts, and the organisation has 40,000 people in debt management plans at any one time. 'Virtually all of those have credit card debts,' says Walker.

HBoS, Britain's biggest issuer of new credit cards last year, says it will follow suit. But a spokesman added that the group would also like information about defaulted utility and council tax bills and student loan payments to be made available to lenders.

The Student Loans Company, which has some 59,000 customers in arrears and bad debts to the tune of £162.5 million, is not allowed to reveal the identity of graduates who default on their loans.

But Ralph Seymour-Jackson, chief executive of the SLC, has asked the Department for Education and Skills to change the rules to enable the organisation to provide lenders with the names of defaulters.

Egg backs the initiative, but is calling for the DfES to go further by sharing full data including balances and behavioural details. This would not prevent students or graduates from falling into debt, Egg admits, but would signal to other lenders not to advance money to those already in trouble.

'By the summer of 2009, students could be graduating with debts relating to tuition fees of £9,000. If you add any further borrowing to cover living costs then loans could run into the tens of thousands for many students. It is in everyone's interest for banks to make the best lending decisions and to do this they need to be aware of a customer's existing financial position.'

What the banks will reveal

· How much is being spent on the card each month

· How much is being repaid each month

· How much is being taken out

· Any increases or changes to credit limits

· Any cheques sent for payment which bounce

· How many people can use the card