We're building a site with PayPal Payments Pro and the client would like to issue shipping charges after the payment for merchandise once the exact shipping charge is known.
Reading around it sounds like Reference Transactions may be the answer here.
According to this article it sounds like an admin could login and initiate a charge (given the use of a Reference Transaction API call to begin with.. I think.. Or perhaps the call isn't needed if we're planning to use the PayPal admin).
Is this possible? Do we even need a Reference Transaction API call, or do we just need to be approved for Reference Transactions, given the plan to issue subsequent shipping charges through the PayPal admin interface?
Please don't answer by suggesting payment calculators or flat rate shipping charges. The question is how to implement a subsequent shipping charge via PayPal.