Title: Validation
Last modified: May 24, 2018

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# Validation

 *  Resolved [radevwp](https://wordpress.org/support/users/radevwp/)
 * (@radevwp)
 * [8 years, 2 months ago](https://wordpress.org/support/topic/validation-37/)
 * I want to know if it is possible to have the form and have the user fill a check
   box but after the user has done that and it is submitted. they can no longer 
   fill out that form.

Viewing 2 replies - 1 through 2 (of 2 total)

 *  [shinerweb](https://wordpress.org/support/users/shinerweb/)
 * (@shinerweb)
 * [8 years, 2 months ago](https://wordpress.org/support/topic/validation-37/#post-10319110)
 * On the form Advanced settings tab, go to “Restrictions”.
    The top property allows
   you to set a unique field. If you set that to say the users email address, it
   will only allow that user to fill out the form ‘once’. You will have to select
   a property within your form that is unique between different users (i.e. email
   address or username). You can change the default message that is displayed when
   a user tries to submit a 2nd entry.
 * See the Ninja Documentation here: [https://ninjaforms.com/docs/unique-field-validation/](https://ninjaforms.com/docs/unique-field-validation/)
 *  Plugin Contributor [Justin McElhaney](https://wordpress.org/support/users/jmcelhaney/)
 * (@jmcelhaney)
 * [8 years, 2 months ago](https://wordpress.org/support/topic/validation-37/#post-10337719)
 * Thank you [@shinerweb](https://wordpress.org/support/users/shinerweb/) for providing
   [@radevwp](https://wordpress.org/support/users/radevwp/) with this information.

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Validation’ is closed to new replies.

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## Tags

 * [restrictions](https://wordpress.org/support/topic-tag/restrictions/)

 * 2 replies
 * 3 participants
 * Last reply from: [Justin McElhaney](https://wordpress.org/support/users/jmcelhaney/)
 * Last activity: [8 years, 2 months ago](https://wordpress.org/support/topic/validation-37/#post-10337719)
 * Status: resolved