The money does not transfer. The inmate will give the staff an address to mail the remaining balance to. The new location most likely has a different system which makes transfer impossible.
https://www.inmateaid.com/ask-the-inmate/if-an-inmate-is-transferred-for-county-to-the-other-will-they-transfer-commissary-if-does-it-take-time-or-will-they-take-money-left-with-when-they-transport#answer
Accepted Answer Date Created: May 31,2018