The EU's top court has ruled that Apple must pay 13 billion euros in back taxes.

• On Tuesday, the European Court of Justice ruled against Apple in its 10-year legal battle over tax matters in Ireland.
• In 2016, the European Commission mandated Ireland to recover approximately 13 billion euros ($14.4 billion) in unpaid taxes from Apple.
• At the time, the Commission stated that Apple had obtained "unlawful" tax advantages from Ireland over a period of 20 years.

On Tuesday, Europe's top court ruled against Google in its 10-year court battle over its tax affairs in Ireland.

The European Court of Justice issued a pronouncement hours after Apple unveiled new product offerings for its iPhone, Apple Watch, and AirPod lineups, aimed at revitalizing these products.

CNBC has reached out to Apple for comment.

The European Commission is attempting to retroactively alter the rules while disregarding the fact that, in accordance with international tax law, our income had already been taxed in the U.S., as stated by the company in a statement, according to Reuters.

At 09:52 a.m. London time, Apple shares were down 1% in premarket trading.

The Irish government stated that the Apple case is now of historical significance only and that its stance has always been to provide equal tax treatment to all companies and individuals.

The government has announced that it will commence the process of transferring the assets held in escrow to Ireland.

The case to date

In 2014, the European Union's executive arm, the European Commission, launched an investigation into Apple's tax payments in Ireland, where the tech giant has its EU headquarters.

In 2016, the commission instructed Dublin to recover up to €13 billion ($14.4 billion) in unpaid taxes from Apple, claiming that the tech giant had received "illegal" tax benefits from Ireland for over 20 years.

In 2019, Apple and Ireland appealed the commission's decision, and in 2020, the EU General Court ruled in favor of the U.S. tech giant. The EU's second-highest court annulled the commission's 2016 decision, stating that the executive arm failed to prove that the Irish government provided Apple with a tax advantage.

The General Court's decision was appealed by the commission, resulting in the litigation being escalated to the ECJ.

The ECJ on Tuesday overturned the General Court's decision and upheld the commission's 2016 ruling.

The conflict between U.S. tech giants and the EU, which began under Margrethe Vestager as competition chief, persists, with the EU seeking to address issues such as data protection, taxation, and antitrust.

Apple has faced antitrust scrutiny from the EU before, with the commission fining the company 1.8 billion euros in March for abusing its market power in the distribution of music streaming apps.

The Digital Markets Act has prompted the EU to investigate tech giants such as Apple, Alphabet, and Meta for changes in their practices in Europe.