Yes absolutely. As @msinger stated any sUAS you intend to fly Commercially has to be registered as such. Since no aircraft can have "multiple" Reg# you simply remove your hobby registration # and replace it with your new Commercial Reg#. The beauty of Commercial Registration is one # works for both types of operations so you can fly under hobby rules or commercial rules with the same aircraft. The only caveat is you can't mix/match the rules in one flight. Take off using Hobby rules the flight must be completed under those rules and vice versa.
I registered the first week for free. I paid $5 and they gave it right back.
Today I went to the web site to re-register as the certificate in my pocket expires tonight.
I looked all over for the 'give us your money here' button, never found it.
I did reprint my certificate and the expiration is now 12/2020.
Two more years for free!