IP limitation helps prevent spam users and restricts the number of submissions made from the same IP. By default, users can submit your form an unlimited amount of times from the same IP address.
To avoid this, access your form builder account, go to Security → Submission Limit and check to Limit the number of submissions from the same IP. Next, add the number of times the form can be submitted from the same IP per hour, day, week, month, year, or eternity.
If you choose to limit form submissions from the same IP per day it means that after 24 hours the limitation is reset. The user will be able to send new submissions, but only the amount you have set in the Security settings.
If you choose to limit form submissions from the same IP per eternity, each user will be blocked from sending new submissions, when the limit has been reached.
Case scenario: You’re an Internet provider and you want to acquire some information from your clients through an online form, during a six-month period. Your database is built upon gathering IP addresses, therefore you require each submission to be unique by its IP address. In this case, you will limit the number of submissions from the same IP to 1 per eternity. This way you will receive at the end the correct number of clients your company is serving.