- JotForm SupportjonathanAnswered on August 26, 2016 at 09:43 AM
You can use the Unique Submission feature of the form.
User guide: How-to-Set-Unique-Submissions-on-a-Form
When using the Unique submission feature, the user who had already submitted form will not be able to submit again the form unliess you remove Unique Subission on the form.
Hope this answers the question. Let us know if you need more help.