Hey @zee​ Racheal from the support engineer team here 👋

Is it possible that the import is updating already existing leads? If you do not use user_id for your leads and there is an existing lead with the same email address, we will update the lead instead of creating a new one.

It is updating some existing leads, but at least half the list is new users that haven't been added to intercom.

If some users don't have user_id, they won't be added?

50% of the list are non existent, but did not contain user_id.

Is this reason? Do i need to attach user_id to each import?