It took eight years and eight months of intense negotiations for 137 countries to agree the global tax deal they signed in October. Hailed as the most important international tax reform in a century, now comes the hard part — implementing it.

If that happens, governments around the world will gain an extra $150bn a year of corporate tax revenues. Although multinationals will pay more, they will get a level playing field — ensuring their competitors cannot pay less than they do. And some of the public anger roused after the 2008 financial crisis by multinationals’ use of tax havens will be assuaged.

“The international tax system badly needed reform,” said Janine Juggins, executive vice-president of global tax and treasury at Unilever. “It’s in everyone’s best interests to move to a more stable system,” she told the FT Global boardroom conference in December.