Sage 300

How do I record sponsorship goods received (zero invoice value) in a system with only financial modules installed?

I already have the default setting that prevents an invoice from being entered twice, but is there a way to extend this to prevent duplicates across all companies in our system? Almost all of the bills that come to my office are addressed to 1 company…

Can we reverse an AP Invoice which is posted in Sage 300, if so how to? Thanks in advance Nishanth