The decision is the latest in a series of European Commission investigations into EU member states that negotiate so-called "sweetheart deals" with multinational companies to reduce their tax bills in member states.
Thirty-five mainly European companies — including the International brewer Anheuser-Busch InBev — had made use of the Belgian scheme.
"In essence, the scheme allowed companies to pay substantially less tax, simply because they are multinational and could benefit from alleged synergies," Margrethe Vestager, EU competition commissioner said.
Commission conclude that Belgian "excess profit" #tax scheme is illegal. 700 mio euro to be recovered from 35 companies, mostly European— Margrethe Vestager (@vestager) January 11, 2016
"National tax authorities cannot give any company, however large or powerful, an unfair competitive advantage compared to others. This means that national tax authorities cannot establish tax schemes that only benefit a select group of companies, in this case, multinationals.
"Such schemes put smaller competitors at an unfair disadvantage. They are active in the same markets and have to pay their taxes fair and square, according to normal tax laws," she said.
In October 2015, the Commission ruled that Luxembourg and the Netherlands have granted selective tax advantages to Fiat and Starbucks, respectively. The Commission also has three ongoing in-depth investigations into concerns that tax rulings may give rise to state aid issues, concerning Apple in Ireland, Amazon in Luxembourg and McDonald's in Luxembourg.
Despite the latest ruling over Belgium, European lawmakers on the TAXE committee investigating tax evasion by multinationals have expressed frustration with the lack of cooperation from some multinational and even some member states.
On publishing its draft report in September 2015 TAXE committee rapporteur Michael Theurer said:
"During the hearings held in different member states, experts confirmed to us that certain member states knowingly implemented and exploited tax regimes to attract businesses."
Among the companies refusing to give evidence to the European Parliament were: Amazon, Anheuser-Busch InBev, Barclays, Coca-Cola, Facebook, Fiat Chrysler, Google, HSBC, Ikea, McDonalds, Philip Morris, Walmart and Walt Disney.