Premanand Maharaj Ji

If the soul is one and never bound, then whose moksha happens?

Moksha is letting go of a mistake

Moksha is letting go of the mistaken belief that you are the body. The soul was never actually bound, so only this mistake falls away.

The feeling that 'I am the body' has formed. The dropping of this mistake is itself moksha. Even in this state, the soul has never been bound.