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, it is not possible to achieve your complete requirement. We only have features where you can limit multiple submissions from one IP address but it is not possible to limit submissions from one IP per month.
You can take advantage if our "Unique Submission" feature and set it to check "Strict check" which will not allow multiple submissions from one IP address. The following guide should help you: http://www.jotform.com/help/64-How-to-Set-Unique-Submissions-on-a-Form
Hope this helps.
Do get back to us if you have any questions.