All of Canberra's 211 new parking meters were affected by the problem on Tuesday morning, which involved at least nine suburbs.

The parking machines are now back online but a spokesman for the government said they had not yet worked out how much revenue had been lost or who would pay it.

The outage took place between 7am and 9.45am and affected electronic meters in parts of Kingston, Acton, Civic, Reid, Woden, Dickson, Phillip, Belconnen and Tuggeranong.

A spokesman for Minister Simon Corbell said the problem was not limited to the ACT.

He also said the issue was not with the machines themselves but was related to the ''gateway'' that provides access to banks.

"Telephone and data transfers are subject to line or mobile tower outages," he said. "The problem [was] similar to what consumers may experience when an EFTPOS device goes offline at a supermarket."

He said the issue was rectified by 9.45am and the estimated loss of revenue is now under investigation.

The spokesman said people had not been required to return to their vehicles to purchase a ticket when the machines were returned to normal and those who had attempted to buy a ticket would not be issued with an infringement notice.

He said parking officers had continued to operate in other parts of Canberra.

The problems with credit card facilities at the new parking machines were first reported on Twitter early on Tuesday morning.

After the issue was revealed, a spokesman for Minister Corbell said all parking meters using credit card payments were out of order and motorists who were unable to process their ticket could park for free.

However, as the fault was electronic, older parking meters that use coins were still functional and could be used to buy parking tickets.

The Justice and Community Safety Directorate said "the fault appears to be a problem with the supplier's systems" and that "urgent work is being undertaken to ensure the machines are restored to normal as soon as possible".