Companies worldwide could collectively pay almost 14 percent more in corporate income taxes annually if a global tax accord is fully implemented, according to new estimates from the International Monetary Fund (IMF).

The IMF's projections foreshadow a sharp increase in corporate tax collections largely tied to a two-part pact struck last year with nearly 140 countries to implement a 15 percent minimum tax rate and an overhaul of some global taxing rights to require some of the largest companies to book income in the countries where revenues are generated.

The minimum tax would increase corporate tax payments worldwide by about 5.7 percent—or roughly $150 billion, according to the IMF's estimates. Corporate tax revenues could increase an additional 8.1 percent because of reduced tax competition—meaning that companies have less incentive to use complex business structures to stash income in lower-tax countries because of the worldwide floor of 15 percent.