Data breaches have become a defining risk of modern digital life. The Marriott breach is one of the most significant in recent memory — and if you've ever had an account with the affected service, your personal data may be circulating among cybercriminals right now.
This guide explains exactly what happened, what data was taken, and how you can check whether your information was exposed — for free, in 30 seconds.
What Happened?
The details of this breach are covered in the FAQ section below, where we answer the most important questions clearly and concisely. The key facts: who was affected, what data was taken, how attackers got in, and what the consequences have been.
Why Does This Still Matter?
Many people assume that because a breach happened years ago, the risk has passed. In reality, stolen data is sold, traded, and reused for years after a breach. Credentials from old breaches are used in credential stuffing attacks — automated attempts to log in to your other accounts using the same email and password combination.
If you reused the same password across multiple sites, one old breach can unlock dozens of your current accounts.
How to Check If You Were Affected
The fastest way is to use our free breach checker. Enter your email address and we'll scan it against known breach databases instantly — no signup required.
If your email appears in a breach, you'll see exactly which breaches affected it and what type of data was exposed. That tells you precisely where to start.
What to Do If You Were Affected
If your data was in this breach — or any breach — take these steps:
- Change the affected password immediately — especially if you reused it anywhere else.
- Enable two-factor authentication on every account that supports it, starting with email and banking.
- Check for suspicious activity on financial accounts if payment data was involved.
- Be alert for phishing — attackers use breach data to craft convincing personalised scam messages.
- Freeze your credit if your Social Security number, passport, or government ID was exposed.
Frequently Asked Questions
When did the Marriott data breach happen?
Attackers first gained access to the Starwood guest reservation database in 2014, four years before Marriott acquired Starwood. Marriott discovered the breach in September 2018 and disclosed it in November 2018.
What data was stolen in the Marriott breach?
Up to 500 million guest records were potentially compromised, including names, addresses, phone numbers, email addresses, dates of birth, passport numbers, Starwood Preferred Guest account information, arrival and departure dates, and some payment card details.
Why is a passport number exposure especially serious?
Unlike a password, you cannot easily change your passport number. Exposed passport numbers can be used for identity fraud, fraudulent loan applications, and border crossing attempts. If your passport number was exposed, consider notifying your country's passport authority.
How do I check if I was affected by the Marriott breach?
Enter your email address in the free checker at Scan My Shadow. If your email appears, monitor your financial accounts and consider a credit freeze if you stayed at Starwood properties between 2014 and 2018.
What was the fine for the Marriott data breach?
The UK's ICO initially proposed a £99 million GDPR fine, later reduced to £18.4 million in 2020. The US had no equivalent federal data protection law, but Marriott faced class-action lawsuits that resulted in a settlement.
Sources
- Marriott – Official breach notification site
- ICO – Marriott penalty notice
- Have I Been Pwned – Marriott breach entry