My understanding is that as Corp, I can score an agenda at the beginning of my turn, or after any of my actions.

If I have have the required advancement tokens on Priority Requisition, but don't score it immediately, can I wait until a run is made on that server, and score my agenda at that time for the free ice rez? Or does "completing an action" imply that it must happen on my turn?

I have a feeling that it must be done on my turn, but wishful thinking has led me to ask the question.

Page 13

Scoring Agendas– When the number of advancement
tokens on an agenda is equal to or higher than its advancement
requirement, the agenda is fully advanced and the
Corporation can score it. The only times the Corporation can
score an agenda is right before his turn begins, or after he
completes an action.

Also refer to page 32 of the rulebook. I typed in AGENDAS CAN BE SCORED as I was not able to copy the pictures used on page 32.

C orporation’s Draw Phase

AGENDAS CAN BE SCORED
Turn begins (“When your turn begins” conditionals meet their trigger conditions)
Draw one card
2. Corporation’s Action Phase
Take actions
After each action: AGENDAS CAN BE SCORED
Phase ends after abilities are triggered following the last spent action

So my wishful thinking was just that. Thanks for the response.