ILR-what fee are IND entitled to charge for a variation?

[ben_scaro]

If we are varying an ILR application to include an additional ground, in this case an undecided discretionary ILR claim to include the additional ground of ten years lawful residence, what fee can IND charge, and what is the legislative basis for it, ie, in the substantive Acts, Immigration Rules or IDIs ?

IND seem to be telling us to use a SET(0) for the variation - this is a danger signal to me that they may mistakenly try to treat the variation as a withdrawal of the existing claim - also done on the SET(0) - which we do not want to do.

Any advice or comment gratefully received.

Ben