How do I create a Sandbox account for Payflow Pro (US, AU) or Website Payments Pro Payflow Edition (UK)?

Create a sandbox test account and then submit a ticket to PayPal Technical Support to link the Payflow and sandbox accounts together.

To create a test Payflow Pro account, follow these steps: 

1. Log in to your PayPal Manager account and verify that your account is active. 
2. Log in to the PayPal Developer Portal. 
3. Set up Business and Personal Sandbox test accounts. 
4. Submit a Technical Support ticket and ask to have your Payflow Pro (US,AU) or PayPal Website Payments Pro Payflow Edition (UK) account linked to the PayPal sandbox business account you set up. Provide the email ID you used when you created your business account in sandbox. 
5. Once you're notified that your account has been updated, you can test against the sandbox test environment by using the Payflow Pilot endpoint.