The Child Support Agency (CSA) has collected or arranged more than £100m in maintenance in a single month for the first time ever, according to the government.

The CSA – responsible for relaying child support payments between separated families - has begun to improve its clearance rate thanks to an Operational Improvement Plan designed to make it more efficient.

First created in the 1990s, the CSA has had a history fraught with failure. The Department of Work and Pensions estimated last year that some £3.5bn of maintenance payment had not been collected by the agency since its inception, 60 per cent of which is now considered uncollectable, largely due to IT problems.

But the government says annual child maintenance payments have soared by 42 per cent year with £1.13bn being collected or arranged by the agency in the year to March 2009, and the recovery of maintenance arrears has more than doubled annually to more than £158m in 2008/9.

The CSA is now overseen by the Child Maintenance and Enforcement Commission.

"Thanks to the commitment shown by the agency's people, I believe that we have started delivering results that instil greater confidence in the child maintenance service," said Child Maintenance Commissioner and former CSA chief executive Stephen Geraghty.

"These are firm foundations on which the Child Maintenance and Enforcement Commission will build as it develops the entirely new maintenance scheme that will replace the CSA's schemes from 2011."

The second phase of the improvement scheme will see £50m worth of new systems from Indian supplier TCS as the commission looks to replace the IT that caused the CSA so much trouble.