Most do not have access to foreign currency, such as US dollars or the South African rand, now demanded by shopkeepers for payment.
A sign outside a supermarket in Harare’s wealthy northern suburbs informed the public on Sunday that, like many other shops, it would not accept cheques or debit cards, because they take too long to clear while the Zimbabwe dollar plunges hourly.
Weeping with frustration, a well-dressed woman fled the shop in tears as she was left unable to buy anything, despite having amassed Z$14 billion for her weekly shop. But even cash was useless, and the shop manager told her he was only accepting US dollars.
"I felt really terrible telling her this, she is a good customer, a really nice person, but it is too difficult to sell in local currency," he said. "We don’t know how to mark up goods as the Zimbabwe dollar is worthless now."
All his goods except meat and most vegetables were imported from South Africa and, with 75 per cent tax, payable in foreign currency to the government slapped on every item, many basic items cost four to five times as much as south of the border, even with a relatively low mark-up.
"I don’t even know the rate for the Zim dollar as it changes by the hour," he said. "We have no alternative but to try and stay alive by charging in US. I am really feeling the strain and I can see customers, and many are old friends, are suffering. Some of them used to be quite well off."
The country’s hyperinflation is driven by the central bank creating ever more money to fund the government’s activities. Even though the authorities chopped 10 zeroes off the currency in August, its interventions and regulations have created a bewildering array of black-market exchange rates.
For cash notes, which the price rises mean are in appallingly short supply despite the printing presses working overtime, on Sunday £1 was worth around Z$110,000. But for cheque transfers, £1 brought anywhere from Z$8 billion to Z$32billion.
At independence in 1980, the Zimbabwe dollar was worth more than the US dollar, but Robert Mugabe’s regime has destroyed the economy, with the slide accelerating in recent years, months and weeks.
John Robertson, an independent economist, said the Zimbabwe dollar’s current plunge was unprecedented. "We had seen it losing value at about 25 per cent a day, now it is losing hundreds of per cent an hour. It is now a valueless currency."
A Zimbabwean businessman said: "The Reserve Bank is looting, that is what caused this end-of-game crash. The Zim dollar lost three zeroes in a week. Now you can fly from Harare to Victoria Falls for US 20 cents."
For ordinary Zimbabweans life has become almost impossible. Bank cash withdrawals are limited to a maximum Z$50,000 a day – enough to buy two bananas from street vendors, who are still selling in the local currency, but 0.000625p at the cheque rate.
Companies are only allowed Z$10,000, or half a banana in street value.
Shops have begun refusing to accept Zimbabwean dollars in any form.
A businessman said: "When supermarkets have to start paying their workers in US dollars they will have to close. When the civil servants demand foreign currency wages, then that will be the end of the road for Mugabe."
Southern African leaders meanwhile meet in Harare on Monday for an emergency summit on Zimbabwe’s political stalemate. Mr Mugabe, the opposition leader Morgan Tsvangirai and the former South African president Thabo Mbeki will discuss implementing a power-sharing agreement, although hopes for progress are slim.