Hotel giant Marriott International is to be fined £99m following a massive data breach which came to light last year.

The Information Commissioner’s Office (ICO) said the personal information of 339 million customers was compromised and today issued a notice of its intention to fine the US hotel group.

It comes just days after the ICO issued a £183m fine to British Airways for the theft of customer data from its website last year.

The IT systems of Starwood Hotels were hacked in 2014, before Marriott acquired the hotel group in 2016, but the data breach was not discovered until last year.

The ICO’s investigation found that Marriott “failed to undertake sufficient due diligence” when it bought Starwood and should have done more to secure its systems and issued the fine for “infringements of the General Data Protection Regulation (GDPR)”.

Around seven million British customers were affected by the breach and 30 million were based in Europe.


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Information commissioner Elizabeth Denham said: “The GDPR makes it clear that organisations must be accountable for the personal data they hold. This can include carrying out proper due diligence when making a corporate acquisition, and putting in place proper accountability measures to assess not only what personal data has been acquired, but also how it is protected.

“Personal data has a real value so organisations have a legal duty to ensure its security, just like they would do with any other asset. If that doesn’t happen, we will not hesitate to take strong action when necessary to protect the rights of the public.”

The ICO said Marriott co-operated with the investigation and has made improvements to its security arrangements since the breach.

The company will have the opportunity to make representations to the ICO before it takes its final decision.

Marriott International’s president, Arne Sorenson, said: “We are disappointed with this notice of intent from the ICO, which we will contest. Marriott has been co-operating with the ICO throughout its investigation into the incident, which involved a criminal attack against the Starwood guest reservation database.

“We deeply regret this incident happened. We take the privacy and security of guest information very seriously and continue to work hard to meet the standard of excellence that our guests expect from Marriott.”