More than 7,000 European companies have endured a bumpy changeover to a new accounting regime this year, its scale exemplified by the experience of Millennium BCP, one of Portugal's biggest banks.

The group's preparations for International Financial Reporting Standards (IFRS) were two years in the making, involved 3,000 people, and extended to Mozambique and Macau, where subsidiaries had to alter the way they recorded transactions. When the first quarter closed, staff had just three weeks before reporting day to consolidate accounts, have them reviewed by auditors, and share the results with the central bank. "It was not a fun time," says an official.