I have seen this question (Unable-to-attend conferences in CV), but the situation is a bit different. In my field, we don't usually submit papers for conferences. Rather, the organizers directly invite a number of persons whom they think interesting to give talks (sometimes participants can contribute talks or posters, but that is not the case here). I received such an invitation, but for a number of reasons am not sure yet whether I will attend.
Can I still add the invitation to my CV?
One could of course argue that it is strange to get credit for something (a talk) I might not do. But one could also think that the invitation itself is a distinction and therefore worth mentioning.