How to prevent duplicate entries in my form?

I would like to prevent multiple submissions to a form.

A user registers (form 1) and is assigned a unique ID. I email the user a customized link (for forms 2 to 4) to allow a session to start/resume the forms.

I've noticed for certain forms there are multiple entries from a user with the same unique ID. I cannot tell if they used the customized link to submit multiple times or after submitting they used the modify link to update their choices and submit again.

I am looking for suggestions on how to prevent these duplicate submissions.

To prevent users from making multiple submissions on a form you need to use Unique Submissions. Here's how:

1. In the form builder, click "Setup & Embed" tab, then "Preferences" button from the toolbar.

2. In the preferences window, click "Form Limits" tab and Select the "Unique Submission" option you prefer

The difference between strict and loose check:

Loose Check - Controls the cookie.

Strict Check - Controls the IP address.

note: If you select Strict Check, people in the same network (in the same school, office, university) will not be able to make submissions, as the IP address for the network would be the same.

3. Click "Close Settings" button and save the form changes by clicking the "Save" button from the form builder.