This article explains why your PayPal sandbox account for Payment Services may not be verified, disabling you from completing sandbox onboarding.
Our onboarding documentation instructs you to sign up for a PayPal account, log into the PayPal Developers account, and then create a sandbox account. If you select to create a new account during onboarding in the PayPal onboarding popup window, PayPal will not be able to verify your sandbox account and you will be unable to complete onboarding.
Steps to reproduce:
You navigate to Payment Services in the Admin and start sandbox onboarding.
In the PayPal onboarding popup that appears, you create a new Business account (instead of logging in with a previously-created PayPal sandbox account during onboarding.
You successfully complete PayPal onboarding.
You see a notification in the Admin that your sandbox payments are pending and that you must confirm your email address with PayPal to complete onboarding.
You did not receive a confirmation email because PayPal was unable to verify your email address.
PayPal will not be able to verify your sandbox account and you will not be able to finish sandbox onboarding (which means you cannot accept payments or test your sandbox mode) if you create your sandbox account before your PayPal account.