How to prevent multiple submissions from the same person?

Please share if you have found a workaround to prevent multiple submissions from the same person.


Oh, this would be incredibly useful! Bookmarked!


Indeed! Looking forward to seeing some of our genius users figure that one out! :stuck_out_tongue:

There’s no real workaround for this one, but there are a few options for identifying duplicate submissions.

The easiest one is by comparing the IP address of submissions - it’s not a perfect solution (people might use the same VPN or be sitting in the same office).

The other method we’ve seen some savvy users use is to prefill a unique ID into a hidden field. That way if a person refreshes the page and submits it again, they’ll still have the same value for that hidden field.


I like the last method. It won’t defeat more motivated adversaries given that it’s right in the URL, but certainly helps weed out quite a few people.

What dean said above is exactly how we do it. When we want to prevent multiple survey submissions, we attach a unique id via Hubspot and are clear that if they share their survey link or have multiple submissions, they will be disqualified.


hi @Ronnie, I wonder how you communicate the Hubspot ID. In my case the Unique ID goes via the URL and a savy user can easily manipulate that number as @danny indicated. How do you approach this?

best, Christiaan