From what I've heard, if you want to renew a lapsed subscription, you'll have to pay for whatever the subscription would have cost while it was lapsed plus 'a bit'. No real idea how much "a bit" is, but that could be a good way to light a fire under your AP folks (or get your boss to light a fire under them, whatever works for you). Altium sales reps seem to have a good bit of leeway, so if you're upfront with your rep about how you WANT to renew but that you just can't drag a PO out of your accounting department in time, they might cut you some slack and skip the penalty.