You can do it in any version since 2012.

Open the batch, press the Reverse button

Thank you.  I don't see where it's done.  Can you point me in the right direction?

Open the batch, press the Reverse button.

Michele - v 20.3.1 sounds like a version number for Sage 300 CRE (formerly Timberline) which is probably why you don't see a Reverse button. This is the forum for Sage 300 (formerly Accpac).  Leave it to Sage to give them almost identical names. 

D'oh! you're right.

You're absolutely correct there is no "reverse" button in this version.  I just confirmed it with Sage.  Thanks wheumann!