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JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.

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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.

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    How to prevent duplicate submissions?

    Asked by GarrettSeepersad on November 06, 2015 at 11:58 PM

    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.

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    JotForm Support

    Answered by Jan on November 07, 2015 at 02:46 AM

    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.