Britain's banks will not close accounts of customers who make a valid complaint, and plan to strengthen their assessment of credit to deter irresponsible borrowing, under a revised voluntary code of conduct.

Groups representing Britain's banks, building societies and payment services firms agreed changes to personal and business banking codes, including not closing accounts after a customer makes a valid complaint. Several banks were accused of closing accounts earlier this year when customers won refunds for charges that had been imposed on unauthorised overdrafts.

The 15-year-old Banking Code is a voluntary code that sets the standard of good banking practice. The revisions to the code will come into effect in March and also include providing more help to customers facing financial difficulties, more clarity on products for unsecured loans and savings accounts, and greater transparency of information for credit cards.