Changing Serial Number After Installation

I am currently running 1 x server with CFMX7.1 and will be rolling out 2 additional servers (dev & mirror) soon. My IT team has ordered the software, but it won't arrive until 2-days before my launch date.

Of course, I need to have legitimate licences on all of the machines, but I want to start testing testing ASAP. Is it possible for me to use my existing SN in the new installations, then change them once the new licences arrive? (I know they should have just ordered the licences

Thanks in advance!
Shaun