The site will tell you when the breach occurred and exactly what information was impacted. A confirmation will then appear, click Continue to finish the process.
You can also sign-up for alerts tied to any of your email addresses, so you will be notified as soon as another breach is picked up by the site. Always create a unique password for every one of your online accounts.
Run by security researcher Troy Hunt – the free database tracks online breaches and allows anyone to check whether their email address has been included in a publicly-available leak.
In this instance, you'll need to enter your Yahoo email addresses to see whether your account has been affected.
So be sure to keep an eye out for an email from the US firm – but beware of any suspicious-looking messages asking you to input any personal data from your account.
If you cannot wait until the company contacts you, it's worth checking the website haveibeenpwned.
For example, take the first letter of each word in your favourite song lyric, phrase or poem – and use those letters, which appear like a random jumble, as your password.
Internet firm Yahoo has admitted a data breach that involved the theft of information from at least 500 million user accounts.An investigation is still ongoing into the breach, which Yahoo said happened in late 2014.