does anyone know how to reject a PO when it’s been in the pending approval state for > 30 days?

Maybe compare {today} to the systemnotes date when the record goes into pending approval

but how can you actually reject it? a workflow?

This could be done via WF.

Yes by workflow use an action based on the saved search criteria that I have told you

got it thank you!

You can reject manually But you need to Create a saved search and check your result

i see. i was told the next Approver can’t access it after 30 days, and I can’t seem to reject as an Admin

do a po search, then attach to WF or maybe a saved mass update? depends on the volume you are dealing with. there are many ways.