Passed my Part 107 exam. Do you have to wait 48 hours to create IACRA application? Why?

So I completed my exam about 3 hours ago. I know the next step is to apply on IACRA for the temporary remote pilot's cert. I've read you need to wait up to 48 hours before you do this. Why? What are you waiting for? via /r/drones https://ift.tt/2OB2gMW