How do companies avoid corporation tax?
5 September 2013 Last updated at 00:15 BST
World leaders are gathering at the latest G20 summit in St Petersburg amid calls for a clampdown on tax avoidance.
Several multinationals have come under fire for paying little or no corporation tax. But how do they manage it?
BBC economics editor Stephanie Flanders explains how the fictitious "Big Bizz Co" avoids high tax bills.