A computer systems problem at HR Revenue & Customs (HMRC) has delayed payments to 50,000 child trust-fund accounts.
Kitty Ussher, economic secretary to the treasury, told a Treasury select committee this week that the delay had been caused by a computer programming error.
A Treasury spokesman said the error was caused by external contractor CapGemini, which runs HMRC's computer systems, but said the problem would not affect any beneficiaries.
"While we are taking the matter very seriously, none of these accounts will be accessed for over a decade and the government will make sure no child missed out," he said.
Only payments to the trust funds of children qualifying for supplementary benefits had been affected, he said, and all these would be paid in full with 8% interest.
The government's child trust fund set up in 2002 will start paying out only in 2010 when the first children included in the scheme start turning 18.
In a statement, Capgemini acknowledged the error and said it had apologised to HMRC and had agreed to fully compensate the HMRC.
"We would also like to convey our apologies to the families involved, and we are working with HMRC to ensure that the payments due are made as quickly as possible," the statement said.