JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You can do that by following:
1. Go to your form builder.
2. Click Preferences:
3. And on Advanced tab you can choose in Unique submission field that submissions come from unique IP address:
Hope it helps.
Let us know if you have further questions.