How can I restrict form respondents to only filling out the form once?

is there a way to allow user only to fill the form one and only times? 

Its for registration as lucky draw winner, only 1 fill up allowed.

Hi pinpin8128,

Thanks for reaching out to Jotform Support. You can use the Unique Field feature which allows you to set limits based on an answer from a specific field. For example, accept unique email addresses or prevent someone from submitting the same data on a Short Text Entry element. So when someone submits your form with the same information from the selected Unique Field, they’ll get the following warning message.

Another feature you can use is the Unique Submissions to prevent your responders from making multiple submissions in your form. You can set it to the Check Cookies Only option which checks whether the submission came from the same browser. It uses cookies stored in the user’s browser’s storage to verify duplicate submissions. Or you can set it to Check Cookies and IP, which means the form checks whether the submission came from the same browser and IP Address.

Please note that by setting it to the Check Cookies and IP option, people in the same network (in the same school, college, university, or institution) will not be able to make submissions, as the IP address for the network would be the same.

Here's how to access the two stated features in Form Settings: 

1. In Form Builder, go to the Settings tab at the op.
2. Click the Show More Options button.
   
   
3. Scroll down and find the Unique Submission or Unique Field features.
   

If that’s not exactly what you’re looking for, can you explain a bit more so I can help you better? 

Let us know if you need any more help.