Why is the payment I received under review?
PayPal reviews all transactions to help sellers avoid risk. If we think that a payment might be risky or fraudulent, we'll review it and ask you to wait until our review is complete before shipping. The review process usually takes less than 24 hours, but sometimes can extend to 48 hours.
We'll let you know by email and/or on the Transaction Details page when it's ok to ship an item that's been under review. Payments that clear Payment Review are automatically eligible for Seller Protection as long as the transaction follows Seller Protection guidelines.