The European Union is demanding that U.S. coffee chain Starbucks and carmaker Fiat repay up to 30 million euros ($34 million) in tax breaks they received from EU nations, in a major ruling to cut down on tax deals global multinationals often shop for.

EU antitrust Commissioner Margrethe Vestager said Wednesday in support of the ruling that "all companies, big or small, multinational or not, should pay their fair share of tax."

The Commission polices state aid and antitrust laws and has been tightening loopholes in EU legislation that have allowed multinationals avoid millions in taxes. Vestager says the Netherlands will have to recoup the unpaid taxes from Starbucks and Luxembourg from Fiat.

She said the EU is investigating similar tax practices in all of the bloc's 28 nations.