Start-ups, telecommunications giants, supermarkets and postal services are all getting into banking, but they concede they are not really disrupting big lenders or dominant card networks because most have to rely on banks or Visa and MasterCard to provide financial services.

Post Office UK launched Post Money in January. Nick Kennett, the head of financial services, said his division, which includes mortgages, foreign exchange and credit cards, accounts for a quarter of Post Office's revenue. But all its banking services come from the Bank of Ireland.

"[Post Office] doesn't now have a balance sheet to support a bank," he told the RFi Payments Innovation Forum in Sydney on Tuesday. Post Office used to own Girobank, but it was sold to Alliance & Leicester Building Society in 1990. "What we're now doing is we're selling services and, hopefully getting some value on the way through from those customer services."

But while banks have been closing branches, Post has to have a branch within three miles of 99 per cent of the United Kingdom's population by law. So, it has 11,500 branches and has been refurbishing many to offer private rooms to discuss customers' financial needs. Other financial services companies also use Post UK's branches.

Coles head of payments Shane Harris said the main reason the supermarket giant had installed contactless terminals and launched a mobile wallet for contactless payments – tap and go payments now make up 80 per cent of all credit card payments in its stores – was to get rid of cash because it is a big cost. "For us [contactless] was around disrupting cash," he said. "Cash is now about 54 per cent of all of our transactions and declining at 11 per cent compound in the last three years."