Facebook's UK business paid just £4,327 in corporation tax last year, despite paying its staff an average £210,000 in wages and bonuses.
The company's share bonus scheme saw employees take home more than £35 million in bonuses. But Facebook's British arm made a loss of £28.5m last year, meaning just £5,000 was due to be paid to HM Revenue & Customs in corporation tax.
The share bonus scheme is understood to be worth around £96,000 per worker, taking average earnings to more than £210,000.
Facebook is one of a number of US tech giants that have been accused tax avoidance in the UK. And John Christensen, director of campaign group Tax Justice Network, said "it's very likely they're using all the usual techniques to shift profits around".
Facebook denied any wrongdoing. A spokesperson said: "We are compliant with UK tax law, and if fact in all countries where we have operations and offices. We continue to grow our business activities in the UK.
The Chancellor George Osborne has repeatedly insisted his efforts to tackle tax avoidance as a priority for government. Despite reducing corporation tax from 28% to 21% since 2010, Mr Osborne has introduced the 'Google tax', or diverted profits tax, aimed at preventing the US tech giants from making their tax liabilities in the UK as small as possible.
But Mr Christensen does not believe that such measures will have a real impact. He said: “They will have to change their model. The Google tax will probably close off some opportunities, and the BEPS rules are certainly moving in the right direction.”
The BEPS rules are a set of rules drafted by the Organisation for Economic Co-operation and Development (OECD) to crack down on "base erosion and profit-shifting".