Docs
Scope
PayPal returned API error code 11451 - Billing Agreement ID or transaction ID is not valid.
Summary
PayPal error 11451 happens due to the Reference ID field. It causes the error for one of the following reasons:
To enable this feature, contact PayPal support over the phone and specify the business account in which you would want this feature enabled.
Solution
Check that the billing agreement ID is correct. If it is, inform the customer that a new billing agreement is needed and offer them the chance to sign up for a new billing agreement through Express Checkout.
If one of the below configurations is not setup you might see this error
When a customer subscribes to a product/service from your website for the first time and chooses to pay using PayPal Express Checkout, a PayPal Billing Agreement is created, which has a Billing Agreement ID (BAID). Chargebee associates this Billing Agreement ID (BAID) with that customer. The Billing Agreement allows Chargebee to charge your customers automatically without them having to perform any action (such as logging into PayPal and approving the transaction) during each renewal. In addition, it can be used to pay one-time charges as well. The Billing Agreement does not expire unless the customer cancels it.
Articles & FAQNote: Chargebee uses the default payment method in the customer's PayPal account to charge them.
Reference Transactions
It is mandatory that you have reference transactions enabled in your PayPal business account. A reference transaction is a permission PayPal gives a merchant to collect recurring payments from your customers. Hence, it is mandatory that you have reference transactions enabled in your PayPal Live Account.
This feature will not be enabled by default in your PayPal sandbox account.
To enable this feature, contact PayPal support over the phone and specify the business account in which you would like this feature enabled.
