Home Report, Respond and Recover Responding to a data breach

Responding to a data breach

Published:

Aug 18, 2025

Updated:

AUG 22, 2025

Who can use this content?

Individuals

A data breach occurs when private or sensitive information, such as passwords, credit card numbers, or personal details, is exposed or stolen without permission. This can affect both individuals and businesses, so it is crucial to respond quickly to limit potential damage.

If you believe your information has been exposed, follow these steps to respond to a data breach.

NCSC Toolbox

https://haveibeenpwned.com

Use this free service to check if your email or phone number was in a data breach.

Confirm the breach

First, check if your data has actually been compromised. You may receive a warning by email, from a service you use, observe unusual activity in your accounts, or learn about it through news reports.

Find out what information was leaked

To gain a clearer picture of what was compromised in the breach, consider the types of information that may have been exposed, such as:

  • email addresses along with passwords,
  • bank account information,
  • personal identifiers like your phone number or address,
  • login credentials for services you may use.

What to do next?

Once you have confirmed whether or not your data has been involved in a breach, it is crucial to take the necessary steps to protect your information.

Change your password

If your login information has been compromised, it is very important to change your passwords right away. Make sure to create strong and unique passwords for each of your accounts and do not use the same password for different services.

Use multi-factor authentication

Add an extra layer of security to your accounts, like a code sent to your phone or an app. It makes it much harder for anyone else to get into your accounts. 

Set up MFA

Watch out for suspicious activity

Stay alert with your email, bank accounts, and online services for any signs of unauthorized activity. Be on the lookout for:

  • Unexpected purchases or items on your bank statements
  • Password reset emails that you did not ask for
  • Unusual logins or messages

If you notice anything suspicious, contact the relevant company or service provider right away.

Report It

If you notice anything suspicious, contact the relevant company or service provider right away. This could be your bank or the online account service provider you are using.