Default To F400S F400K F400L (Korean version of G3) users

Hi.
I am thinking to buy LG G3 Korean version but can anyone test about USSD/MMI Code? (For example *100# *118*8# *123#)

I use Prepaid Sim card so if USSD/MMI code does not work then I cannot top up(reload) or check balance or make a subscription...

The reason why I am asking this is because I have used LG G2 and Optimus LTE2 (Both Korean version) and For KT version, it did not work at all and for SKT version only half of the contents were displayed...

So can anyone check whether USSD/MMI code works?

F400L F400S F400K pls...
Motorola Motoroi(Korean version of milestone XT720 ) XT720
Motorola MotoQRTY(Korean version of Milestone ) XT854
HTC Desire A8181
HTC Desire HD A9191
LG Optimus LTE2 (LG-F160K)
LG G3 D855 (Singapore)