Utility dual fuel switching cashback invalidated if you are already with them?

thor

If you already have gas or electric with an an energy utility and decide to go dual-fuel with them, would this be a problem for some of these cashback shcemes that they have? i.e. the t&C may only give cashback for actually switching both gas & electric which can't happen if you are already with them.

KimYeovil

Yes, if you already have one fuel with them you, obviously, will not receive the dual switch cashback. You will still receive the single fuel amount, though, but this is likely to be less than half (and sometimes, as you say, is zero.) You also receive no cashback if you change tariff with the same supplier.