The changes are expected to cost the banks up to $300 million in reduced charges. Major banks may re-direct their portfolios away from Visa and MasterCard, the programs that are most affected, to proprietary programs such as American Express and Diners Club which are excluded from the new program.

Most of the big banks have bowed to the RBA/ACC pressure, with the NAB, Westpac and ANZ conceding to most areas of the new program, including the removal of entry barriers in the credit card market.

Notably, the Commonwealth Bank remains steadfastly opposed to the changes.

Negotiations will start on new interchange fees, which are charged for processing another bank’s transactions. A proposal for new interchange rates has not yet been brought forward.

The Australian Financial Review (AFR) reported: ‘It was revealed last month that NAB has already entered discussions with Amex to explore opportunities for a joint-venture payment card company. At least two other majors – Westpac and ANZ – have since been in talks with Amex.’

Visa has warned it may sue the Reserve Bank of Australia if the reforms damage its economic appeal.

‘If Visa sees its fundamental business interests being compromised, then litigation is a strong option,’ said Visa’s director of corporate communications, Peter Vicary.

‘We see this as having a long way to go,’ Vicary told the AFR