The problem, on deadline day for personal tax form returns, forced HM Revenue & Customs to extend the deadline by 24 hours to enable people to complete their forms without receiving a fine for late submissions. HMRC has not disclosed the exact nature of the fault.
HMRC had planned for a "significant increase" in tax returns around the deadline, Tim Burr, National Audit Office Comptroller wrote in his report on HMRC's 2007 to 2008 accounts. But in spite of the plans, the system was still unable to cope.
"The department secured assurances from its supplier that the online service could be supported at the expected volumes at the peak period. However, on the day the hardware problem meant that the level of customer attempts to use the online service could not be supported." Capgemini supplies IT to HMRC under the Aspire contract, which aims to overhaul technology and reduce running costs.
In a statement, HMRC and Capgemini told Computerworld UK: "The technical issues were caused by a hardware problem which was triggered by a spike in logins. Our systems had been thoroughly capacity tested but this hardware problem meant that we did not manage the January 31 peak as well as we would have liked."
They said the hardware was replaced in February, as part of an ongoing program to improve HMRC's website. The tax office wants all returns from businesses and "IT literate individuals" to be filed online by 2012. Some 3.75 million tax returns were filed online this year, including 204,000 on 31 January.
In April, HMRC also updated the online returns software as part of plans to put it onto a new, undisclosed platform. Both HMRC and Capgemini have reviewed how online services are tested "to ensure peak demands are met in the future."
"We have enhanced our testing procedures and the robustness of our infrastructure in advance of the Jan 09 filing peak," they said.
HRMC is also undertaking "a wider review of lessons learned to enhance the speed with which it responds to such events," Burr at the NAO wrote.
The news comes as the NAO refused to sign off HMRC's accounts, after the tax credit scheme lost GBP 1.5 billion (US$3 billion) in 2006 to 2007 on overpayments and fraudulent claims.
Last week, HMRC postponed the rollout of a GBP 140 million pay as you earn processing system because it was not ready. The system was part of an ongoing transformation program, in which the NAO questioned the realism of HMRC's aims of saving GBP 11.5 billion by 2011.
Related content:
UK government admits to online tax filing system failure
Glitches plague CRA's online tax system
EXCLUSIVE: What went wrong at Canada Revenue Agency
icon.
