The HMRC spent 44 percent of its 2009-10 supplier budget on an IT outsourcing deal led by Capgemini.
Overall, HM Revenue and Customs (HMRC) spent £1.75bn on suppliers in the last financial year.
The figures, which were obtained from the tax-collection agency through the freedom of information act, show the department's spending was dominated by two outsourced deals.
The first was with Aspire for IT, a contract which was signed in 2003 and will run until 2017. The department also splashed out with a company called Mapeley Steps, which provided the HMRC with a PFI contract for the management its property.
However, this didn't come cheap, ringing in at a cost of £333m in 2009-10. Specialist Computer Holdings received £20m in the last financial year was and BT received £15.2m as a result of work with the HMRC. Detica, received £9.2m; Fujitsu £7.2m and Airwave £2.9m.
One name that stands out in the HMRC's spend is Vodafone, which received £1.9m. The company seems to be having a cosy time with the tax department recently.
Last month it was suggested by Private Eye that Vodafone bought a German engineering company called Mannesmann for €180bn so it could use it to avoid paying tax. This move was claimed to have fallen foul of British anti-tax avoidance laws, so to paint itself whiter than white Vodafone got in touch with the Inland Revenue who didn't want to know.
However, the HMRC decided to give a helping hand and allegedly let Vodafone off with, allegedly, at least £6 billion.
Vodafone agreed a tax settlement of £1.25 billion in July to resolve the long-running dispute. It said it has met all its tax obligations and had never received a bill for £6 billion, calling the figure "misleading".
Despite a range of protests organised by UKUncut, which temporarily closed shops throughout the UK, Vodafone has gone on its merry way.
Last week it announced it would be investing in the East London Tech City to advise start-ups. It is understood that the company will seek to help "Mobile Clicks" competition winners to set up here as well as planning to get those who invest in the annual competition to invest in the tech city. It wants to ultimately invest in the next generation of start ups and use the city to do this.
However, there are currently no released details on how much the company plans to spend here.
Vodafone has also not been shy about its profits, boasting today that it has hit and exceeded targets. According to the company its Q2 figures show a group organic service revenue growth of +2.3 percent with improved revenue trends in all regions.
Full year guidance for adjusted operating profit increased from £11.8 billion to £12.2 billion
and free cash flow guidance was confirmed to be in excess of £6.5 billion.