What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
Unfortunately we do not have such feature. It is currently not possible for you to block IP address of any form users. IP address can only be blocked by JotForm which will block the user of that IP address from accessing JotForm site.
Let me send a feature request to our back end team. We will get back to you as soon as we have any update from them. For now you may consider taking advantage of our "Unique Submission" feature to disable multiple submissions from one IP address.
Thank you sharing your thoughts on this feature request. I have moved your question to a new thread and you will be answered here: https://www.jotform.com/answers/836542