Governments need to modernise their tax systems to catch international companies that dodge paying corporation tax, the Organisation for Economic Co-operation and Development has warned. The ease with which companies shift profits around the world to offshore havens shows that tax authorities need to step up their anti-avoidance efforts or risk losing billions of pounds in much-needed revenues, said the Paris-based thinktank…Angel Gurría, head of the OECD, said the G20 needed to act this year to combat avoidance, which he said was undermining the ability of governments to recover from the financial crisis. He said the failure to crack down on "the big guys" would leave small and medium-sized businesses and middle income taxpayers to pick up the tab for vital public services. [Refers to Amazon, Google, Starbucks]