Can You Use PayPal for Payment Plans?
The general answer is no. PayPal works for single-pay purchases and subscriptions, but not payment – unless – you are using PayPal PayFlow Pro as your backend merchant processor.
Here is an article on Infusionsoft's HelpCenter, showing that PayPal (Express Checkout) will work with 1-Pay purchases and Subscriptions, and does not work with Payment Plans.
If you have any questions, please contact us at firstname.lastname@example.org and we can help!