I have an iphone 7 (sprint) which I originally bought on the sprint network but activated on boost. I put my IMIE and it said it was invailid. I'm really trying to switch to VM. Can I do it?
If your phone is currently activated on the Sprint network (Boost) it is not surprising that it would be ineligible.
However, since it is a Sprint-branded phone it might not be eligible in any event even if not activated since Virgin Mobile is part of Sprint.
You could PM one of the Virgin Mobile agents for an authoritative answer.