Many Swedes have completely stopped using cash, relying on digital services like Swish and iZettle to buy and sell items and send cash to each other.

But the central bank has been among those to warn that putting payment systems in the hands of commercial operators could lead to problems in times of economic uncertainty and that some groups - such as pensioners - still rely on cash.

"We cannot let private actors do away with cash," a government-appointed committee said in a signed article in the Dagens Nyheter newspaper.

It said Sweden's six biggest banks should make sure all Swedes had access to cash and the ability to deposit notes and coins without having to travel more than 25 km.

That would cost the six lenders 8-15 million Swedish crowns, it said.

The committee, which is also looking at the mandate of the central bank, said parliament needed to decide how the increasing digitalisation of the payment market should proceed and the role of cash longer term.

Sweden is in the forefront of digital money and many shops, restaurants and even bank branches refuse to accept cash. In the last 10 years, cash in circulation has halved to around 50 billion Swedish crowns ($5.75 billion) from 112 billion.

The central bank is looking at introducing a digital currency so it can maintain its role in the payment system.

($1 = 8.7035 Swedish crowns)

(Reporting by Johan Sennero; editing by Simon Johnson and Jason Neely)