Bank customers are being charged too much to withdraw money from cash machines.
Cash machine operators were given until the end of the year to clean up their act or face the threat of Government regulations.
The warning was issued in a report from the Commons Treasury Select Committee, including Midland MP James Plaskitt.
In a highly critical report issued today, banks and cash machine operators were criticised for hiding warning stickers away so customers missed them.
Warnings of charges often appeared only at the end of process.
The report adds: "Charging machines prominently advertise the ability to make 'free balance inquiries' in an attempt to mislead consumers."
Mr Plaskitt said: "There should be a visible sign on every machine which charges, saying how much it costs to withdraw money.
He added: "Anybody withdrawing money at a post office, should be guaranteed that they will not be charged."
MPs called for the Banking Code be extended before the end of the year covering all charging cash machine operators.
Treasury Select Committee chairman John McFall said: " Access to non- charging machines should be available."
The Association for Payment Clearing Services welcomed the report.