The number of cash machines charging a fee for withdrawing money surged last year, the Association for Payment Clearing Services (Apacs) has said.
There are more than 54,000 cash machines across the UK
Overall, cash machine numbers rose by nearly 8,000 to more than 54,000 across the UK during 2004, Apacs revealed.
However more than 7,000 of the new machines are independently operated, often charging £1.50 to withdraw cash.
The spread of fee-charging machines is being investigated by a committee of MPs, concerned at high charges.
In March, the Treasury Select Committee in a report called for clearer warnings on fee-charging cash machines.
The Committee expressed concern that fee-charging machines are located in poorer areas of the UK, often in places where traditional High Street banks have left.
Overall, consumers now pay £140m a year to access their own money the Committee's report concluded.
Free machine preference
According to Apacs, more than four out of 10 UK cash machines are now operated by independent firms, nearly all of which charge a fee for withdrawals.
In total, the number of independently-operated cash machines rose from 14,436 to 21,683 during 2004.
However, Apacs found that just one in 20 cash machine withdrawals incurred a fee.
"This shows that people are going to free machines operated by banks and building societies over fee-charging machines," Jemma Smith, Apacs spokeswoman, told BBC News.
"The spread of fee-charging machines is about consumer choice. It is worth remembering there are a greater number of free to use cash machines than ever before."
Rosemary Calendar, a spokeswoman for Nationwide Building Society, which has long criticised the spread of fee-charging machines, told BBC News that fee charging machines will soon be in the majority.
"By the end of 2006 we predict the number of fee-charging machines will overtake free machines.
"By 2007 people will be paying £300m to withdraw their own cash. We are going the way of the United States where 40% of withdrawals are charged for."