The government removed £792 million from IT costs over a 12 month period, according to the figures of the National Audit Office.
Over recent months, the government has made several announcements about its savings, but has not explained the figures.
In a report published today, the NAO said audited figures demonstrated a £537 million saving from capital spending on IT, and £255 million from other IT spending. The period concerned is the 2009-10 to 2010-11 financial years.
Additionally, the government slashed £645 million from consultancy expenditure, of which a significant amount includes IT work not counted in the pure technology category.
Around £7.9 billion in total was cut from Whitehall expenditure, including from the IT savings, back office cuts and staff redundancies.
However, the NAO warned that departments would struggle to make longer term savings, because of gaps in their understanding of costs and risks. It also questioned whether the changes signified long term efficiency, or quick cuts.
Additionally, the cost of IT could increase in the future, the NAO said, given the importance of technology to central government functioning and projects.