# Sandbox Customers
You can use the PayFlexi in test mode, which does not affect your live data or interact with the banking networks. The API key you use to authenticate the request determines whether the request is
live mode or
test mode. When you are in test mode, you would be required to use a sandbox or test customer strictly belonging to one of your PayFlexi business accounts to complete test orders and transactions.
# Setting up a Sandbox Customer
If you are testing for the first time you would need to complete a
one-time setup of the sandbox or test customer for your business. To complete this, head over to your developer page and fill in your preferred test credentials. Please note that every sandbox customer has an email address ending in
@payflexi.test and you are able to customize the rest of the email address.
# Signing in as a Sandbox Customer
We offer password-less authentication and single-sign-on features on our checkouts, and as thus we continually require logged-in users on our checkouts to refresh their signed-on status by providing authentication passcodes sent to them via emails/SMS. For easy testing, and also to fast-track your integrations, these passcodes are not sent in test mode, they are made easily accessible to you on your developer page. The validity of each passcode is always indicated on the page, and you should refresh the page often to check for newer test login passcodes.