SIM "Deactivate" vs. "Release"

Under SIM card management on the console, I have options to “Deactivate” or “Release” the SIM. Which should I use if I want to temporarily suspend billing (I’m planning to use a third party SIM). I don’t want to accidentally make the SIM permanently unavailable to me!

You want to use Deactivate in your case. But, even if you Release it there’s no problem in re-associating it with your account; you just have to go through the SIM setup process again.