I was working with the Paypal sandbox to test a Paypal application for a client. I was using IPN for the payment notification from PayPal so I could update member record on database. While testing I was getting the payment_status value Pending.  I played with the sandbox account after I created it, so things might have got messed up. After searching these steps below seem to have solved the problem getting me payment_status value Completed.

1. Login to your Developer Central.

2. Click on Test Accounts tab on the left. You should have created these test accounts for testing on Sandbox.

3. Find the column ‘Payment Review’.

4. Find the sandbox account you are using  and click on “Enabled” in the ‘Payment Review’ column.

5. This should change to “Disabled” and now payments funded from your balance and credit card will complete instantly.