The checker will ask for some personal information, like your name, email address, as well as the last six-digits of your passport number.

Marriott says data on “fewer than 383 million unique guests” was stolen in the data breach, revealed in September, including guest names, postal addresses, phone numbers, dates of birth, genders, email addresses and reservation information. Later it transpired that more than 20 million encrypted passport numbers were also stolen, along with 8.6 million unique payment card numbers.