People put record amounts of cash into their bank accounts at Post Office branches in March.
Personal cash deposits totalled £1.1 billion in March, beating a previous peak recorded in September, when £1 billion was deposited by personal customers.
The findings were made ahead of more businesses in England reopening their doors on Monday.
Cash withdrawals in March were also higher than they had been in recent months.
Personal cash withdrawals in March totalled £590 million, marking the highest level since last September, when withdrawals totalled £591 million.
Post offices are supporting businesses, pubs and the hospitality sector get back on its feetMartin Kearsley, Post Office
Overall, personal cash deposits and withdrawals were up 22% in March compared with February, according to the Post Office’s cash tracker.
Cash withdrawals are expected to increase significantly again in April as non-essential retail businesses reopen, the Post Office said.
Business cash deposits in March totalled £707 million, up by 21% month-on-month, from £586 million in February.
The Post Office suggested the increase was due to firms adapting their business models during lockdown and finding new ways to continue trading.
More than 11,500 Post Office branches are situated across the UK.
The Post Office has a partnership with more than 30 banks, building societies and credit unions which means that 99% of UK bank customers can access their accounts at their post office.
Martin Kearsley, banking director at the Post Office, said activity is starting to resurface due to pent-up demand built up over the last year, as lockdown restrictions start to ease.
He said: “Post offices are supporting businesses, pubs and the hospitality sector get back on its feet.
“Our branches have remained open long hours, many seven days a week, with the size of our network across the country providing a convenient place to deposit takings.”