Cash deposits and withdrawals are on course to top £3 billion in a month at Post Offices as bank branches are closed.
The Post Office said it handled £2.99 billion of cash in September – the highest amount in a single month so far.
It added that branches have already had the busiest first week for cash ever in October – and deposits and withdrawals are expected to exceed £3 billion this month.
Bank branch closures mean thousands of customers are being directed to Post Offices for their cash needs, the body said.
The Post Office has an agreement with many banks which allows people to do their everyday banking at its branches.
Post Offices handled some £1.06 billion in business cash deposits in September, up by around 3% month-on-month.
Personal cash deposits stood at around £1.2 billion in September, while a total of £685 million was withdrawn over the counter at the Post Office’s 11,500 branches.
On Friday, the contactless card transaction limit will increase from £45 to £100, meaning more opportunities to use tap and go payments where once cash might have been used.
However, a recent Post Office survey found nearly half (44%) of small hospitality and leisure businesses in the UK rely on cash daily.
The Post Office recently launched a “save our cash” campaign.
Martin Kearsley, banking director at the Post Office, said: “Each month brings news of further bank branch closures, and in many communities across the country Post Office is already the last counter in town.
“Despite the impending increase in contactless payments, we know that small businesses in particular recognise the value of cash now more than ever.
“We’re preparing for continued increases at our branches as Postmasters support local businesses in their community by staying open long hours and weekends, providing a convenient and secure place for businesses and the self-employed to deposit much-needed cash takings.”