Some of Whitehall’s biggest computer projects have spiralled out of control, with total cost overruns of more than £18 billion, an investigation by The Times can reveal.

Plans for new computer systems are years behind schedule and have ballooned in cost; others have been scaled back or even scrapped. Yet companies continue to make hundreds of millions of pounds in profit, with £102.3 billion forecast to be spent on government IT projects over the next five years.

The Times studied eight of the largest Whitehall IT contracts, spanning the health service, tax collection, benefits, Armed Forces and the police. Their overall cost to the taxpayer, from original estimates given to MPs to the latest estimates available, has risen by £18.6 billion.

The figures come as the Government prepares for a secret overhaul of one of the most controversial projects, a £12.7 billion plan to computerise all patient medical records.

The programme, which aims to link 30,000 GPs to nearly 300 hospitals, is already four years late. It was originally estimated at £2.3 billion.

Some NHS trusts waiting for software are to be allowed to buy from outside suppliers. “The idea is that trusts in those areas where the contracts are underperforming should have the freedom to purchase their own systems so long as they are compatible,” a Whitehall source said.

It is understood that David Nicholson, the chief executive of the NHS, is in favour of such a move. However, sources close to the project said that this could lead to the current suppliers, BT and CSC, walking away.

Fujitsu, which left the contract in May, is believed to be seeking £600 million from the Government after it was asked to change its product 650 times for no extra fee.

Analysis of other IT projects revealed a similar pattern of budget overruns, delays and disputes.

An IT contract for the tax credit system was originally set by HM Revenue & Customs at £2.9 billion but will now cost £8.5 billion. Another to link MoD databases was supposed to cost £5.8 billion; the latest bill is for £7.1 billion.

The National Audit Office is expected to criticise severely the Ministry of Justice, whose prison project is overrunning by £456 million even though its scope was scaled back. The system that aims to link records for each offender will only be installed in prisons and not shared with the Probation Service, as originally planned.

Whitehall officials say that much of the extra cost is to acquire more services, but MPs and IT experts argue that confidentiality agreements mean that this is hard to test.

Rotherham NHS Foundation Trust — a foundation hospital not bound by the NHS contract – has decided to buy its own patient record system. Brian James, its chief executive, said last month: “We were unable to get any firm dates for the delivery of [the software] Lorenzo.”

The Department of Health said that some trusts could buy interim systems while waiting for delivery of software under the programme.

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