Forty-seven countries signed up Tuesday to automatically share bankdata, including key financial centres Singapore and Switzerland, the OECD said, inwhat has been touted as a major step towards cracking down on global tax evasion.Under the declaration, the 47 countries have committed to "swiftly" pass newdomestic laws that will allow them to collect information on all bank accounts andautomatically exchange it with other participating countries.They must also call on their financial centres "to implement the new single globalstandard without delay". The list of signatories includes all 34 members of the Organisation for EconomicCo-operation and Development (OECD), a club of developed nations thatspearheaded the initiative.That includes Switzerland, Liechtenstein and the British jurisdictions of Jersey andGuernsey -- all which have been criticised for high levels of banking secrecy in thepast, laying them open to accusations that they serve as havens for taxevaders.ThelistalsoincludesLuxembourg, even though it is blocking transparencyinitiatives within the European Union.The OECD has also secured the participation of 18 non-OECD nations, including thekey international financial centre of Singapore.The new global standard was described as "a real game-changer" by OECD chiefAngel Gurria when it was unveiled in February. Previously, countries would have to request data on suspected tax cheats using aprocess that was often complicated and some countries were uncooperative.The United States was the catalyst for the change with its so-called FATCA law whichrequires international banks to provide data on accounts held abroad by its citizens and companies or face sanctions.The next step, the new declaration states, is for the OECD's fiscal committee to provide within the coming months clear guidelines on how the standard should beput into practice, and come up with technical solutions to make sure it is effective.A "Global Forum" is also due to be set up to monitor and evaluate individualcountries' efforts.Developed in cooperation with the Group of 20 gathering of advanced and leadingemerging markets, the system should come into force in 2015."This new standard on automatic exchange of information will ramp upinternational tax co-operation, putting governments back on a more even footing as they seek to protect the integrity of their tax systems and fight tax evasion," Gurriasaid in a statement in February.