Either option will work. I have popped the SIM from old phone to new phone many, many times and it works fine. You can also use the new one if you want, just make sure the old SIM is removed from the old phone and it is powered off....you can't have 2 active at the same time. The new SIM should register with the Verizon network when you first turn the new phone on; sometimes you might see an error and you just have to call customer support and they can fix the error and register the new SIM.
Hello, pappy50. We recommend using your new SIM Card with your replacement device. To clarify, is it now activated?CourtneyM_VZW