Ah, that is how I read it as. 1 action = 1 summon, I didnt even think about that being the hard limit. I was just looking for a specific number that would limit them.
"You can only summon one spirit at a time, and it only hangs around for a limited time—a summoned spirit will return to wherever it was when you called it when it’s either through with all of the services it owes you or when the sun rises or sets (whichever comes first)."
"A magician can bind up to his Charisma attribute in spirits."
Thanks again for the heads up. That throws a couple kinks into my plans. Guess I wont have 8 or 9 unbound spirits doing spell sustains for the day as I do other stuff