Thousands of Birmingham council tax payers have been charged twice this month following a computer error.

The council’s privately-run revenue collection company Service Birmingham has apologised after taking two payments instead of one from 3,447 council taxpayers and business ratepayers.

The Capita-run firm admitted the error and has made refunds to all involved.

Capita has confirmed that the overall amount overpaid was more than £500,000.

And some refunds could take several days to clear through the banks at a time of year when many accounts are at a post festive season low.

Anyone charged for being overdrawn as a result of the error will be compensated.

A spokesman for Service Birmingham, which collects the council tax in the city, said: “Due to a processing error, 3,447 duplicate transactions were made for payments to Birmingham City Council.

“All affected people and organisations were informed of the error, and refunds were made.

“We would like to apologise to those affected and reassure them that we have taken steps to mitigate the risk of this happening again.”

A Post reader, who asked not to be named, said: “I just checked my bank account only to find they had taken my debit card payment twice.

“I rang them up to complain and was told computer error has hit many people and they will return the money in a few days.

“What happens to people who cannot be without hundreds of pounds for a few days?”

Birmingham City Council handed over its council tax collection department to Capita Service Birmingham in 2011 with a commitment to raise collection rates from 96.3 per cent to 98 per cent – ensuring an extra £4.8 million income for the local authority.

It was part of the deal which saw the controversial IT contract with the company extended by five years until the end of the decade.

The error has come at a bad time for Capita Service Birmingham with the contract under the microscope and negotiations under way to cut at least £20 million a year from the bill. Last month the council’s deputy leader Ian Ward announced that officials were working out the cost of ending the contract early and setting up an alternative IT and call centre to compare with the cost of continuing the contract until 2020.

Birmingham City Council has paid £120 million a year to Capita across a range of contracts in recent years leading critics to call for the company to take its share of the local government austerity.

There have also been calls and a petition, started by Aston University professor David Bailey, for the contract to be published online to allow greater scrutiny .

Earlier this month council leader Sir Albert Bore stated that it has always been the intention to publish the contract, with sensitive information redacted, and this would be done as soon as possible.