Identify Visitors without Email - Is it possible?


Hi all,
I am looking at using the Identify Visitor endpoint in our app to assign them to the respective contacts in Hubspot. Ideally though, I would do this without passing publicly identifiable information, that is, using an ID instead.

Hubspot's docs state that an email is required, but then states further down that you can pass an ID instead, with the one limitation being it won't create a contact. That is fine for us, as this is simply aligning existing contacts, but my questions for this are:

  1. Does this mean we can pass an ID instead of an email?
  2. If so, what ID is this? Would it be the Hubspot Contact ID? Or something separate which we will need to match elsewhere? Or another ID completely?

Anybody's experience or insight would be greatly appreciated. The language isn't quite clear to me.


Welcome, @Chris_H!

The language is a bit murky, so I'm happy to clarify further.

You can pass an id instead of an email address, but the analytics data will only be associated with a physical contact record if either:

  • You previously identified a visitor with both an email and the id.
  • You've been associating activities with the id and the visitor converts on a HubSpot form (which requires email).

Thus, email needs to come into the picture at some point. Let me know if you have follow up questions!


I see, so basically this ID is defined and passed with an email during either of those two inputs. So the ID is not the ID of a Hubspot contact.

Thanks for your assistance!


That's correct, @Chris_H. Happy to help!


Going to jump in here as I essentially have the same question. We are attempting to identify users coming from our app to our marketing sites. Many of them do not have emails but do have a unique Id that is also contained in both salesforce and hubspot, plus in a browser cookie set by our app.

So, if a visitor came to our site from our app and the only thing we knew was that ID is there anyway for me to identify/track them before they fill out a form?


Welcome, @stevec!

The HubSpot tracking code will track page views and store them in the hubspotutk cookie, but the data won't be associated with a contact record unless:

  • An email is passed to the identify function. If you also include an external id, you can use the id alone going forward (see below).
  • The visitor has previously had an email associated with the same hubspotutk cookie, either through a past identify event, form submission, or HubSpot marketing email click.

In short, it's not possible to fully track a visitor with an external ID alone — an email address has to be associated with the cookie at some point.