I believe you can add the personalization variable {{ subscriber_id }} in UTM params and it will be tracked in GA. However, you shouldn’t pass any PII anywhere as this is not a good practice. Let me know if that helps.

Thank you for the answer. 
Hmm, okay. It’s because I’m creating a survey and I want the answer from the survey to be linked to the subscriber, in order to segment further later on. 

Do you know a way to do that? 
I’m open for any hackable way. :)

Hi @saksmoto ,

You could try use one of the survey platforms we do integrate with to have the data sync over to Klaviyo. Or utilize Klaviyo's API and a site like Survey Monkey.
You can hyperlink a link to the survey in a button to direct the customer to the survey. More information can be found here: How to Use Links to Collect Information About Your Recipients. Once you integrate a survey site with Klaviyo, you can sync appropriate information to Klaviyo which can be used to analyze the data. 

If you are looking to send out an email that will allow your customers to update an existing property, you can use buttons within the email to do this rather than using a form.
https://help.klaviyo.com/hc/en-us/articles/115005255248-Use-Buttons-in-an-Email-to-Collect-Information-About-Your-Recipients

What you will do is add this tag as the URL within the button:

{% update_property_link 'profile_property' 'property_value' 'redirect_link' %}

Then you will assign the existing property and add the new value for when the customer clicks the button. Then to finish the setup, add a redirect link. When someone clicks the button, their profile property will be updated based on the button they click.

Thank you so much for a great answer! :) 
I’m using a survey platform that is not listed as a Klaviyo integration. It’s called GoZenForms. 
Would I need to use the API to transfer the Information or is there an easier way? 

Hi @saksmoto ,

Since we don’t have a native integration with the, you would have to utilize our API for that.

Thanks!
Alex