The longer your password, the stronger it gets. Although Mercari enforces a minimum password length of 8 characters, we recommend using a password that’s at least 15 characters long and contains a mix of letters, numbers, lowercase letters, and special symbols. Use different passwords for different services. If one of your accounts gets compromised, reusing the same password could allow attackers to access your other accounts. Use a password manager to generate and store unique, strong passwords. For additional security, use multi-factor authentication (MFA).

We will send important information to your phone including two-factor authentication codes for login. Make sure your registered phone number is up to date. If you aren’t sure how to check or update your phone number, see our guide to changing your verified phone number.

Older versions may contain known vulnerabilities that bad actors can exploit to compromise your data. Make sure you install the updates only from official sources.

If you receive suspicious emails or text messages claiming to be from Mercari, please report them by forwarding them to phish@mercari.com. Be vigilant against phishing messages, avoid clicking on links, and do not input any sensitive information on suspicious websites. Read more about phishing here.

If you lose a device logged into your Mercari account, contact us through the app and we’ll take action immediately so no one else can use your account. For more instructions, see our guide to contacting us about a lost device.

Account sharing is strictly prohibited by Mercari’s Terms of Service. Letting someone else use your account may lead to unauthorized access to your personal information, identity theft, and financial fraud.

Regularly check login history and email notifications from Mercari to ensure there are no suspicious logins or transitions you do not recognize. You can check your account’s login history by going to the Login History page.

If you’re registered for iD payments on Merpay, we recommend removing the iD information from the Mercari app on your old device before starting to use your new device. To learn how to do this, see our guide to switching devices.

Confirm that the email address linked to your account is also not compromised and change the password for your Mercari account.

Mercari offers the option to log in using third-party accounts (log in with Facebook, Sign in with Apple etc.). If you use a third-party account to log in to Mercari, make sure that this account hasn’t been compromised and is secured too.

Contact us immediately if you notice any unauthorized transactions on your account or need help securing your Mercari account.

If you are using a physical or virtual Mercari credit card (Mercard), you can request your card to be blocked from the app to prevent abuse.