Upgrade a STD advance to 1st

[13 valleys]

Hi Guys.I have asked the following question on the Twitter pages of X/C,Transpennine Express,VTEC and Virgin Trains.... "If I change my STD advance ticket to 1st class advance for exact same train,do I need to also pay a extra £10 admin fee?" All the Atoc''s said yes,except VTEC.I read the fares advice section and it gives the impression that it is only X/C that charge the fee.Does the fee only get waived if I upgrade to a walk up FDS/FOS?