---
sourceDocument: Xanadu ServiceNow AI Platform Administration
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/xanadu/platform-administration

 Release :

    - xanadu

ft:locale :

    - en-US

ft:publication_title :

    - Xanadu ServiceNow AI Platform Administration

ft:clusterId :

    - platadm

bundleId :

    - platadm

workflow :

    - Platform


---

# Require unique values for a field

# Require unique values for a field {#ariaid-title1}

* Release version: Xanadu
* 
* Updated August 1, 2024
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

The system allows you to require that a field's values be unique. When this is done,
the system will not let two records have the same value for that field.

## Before you begin

Role required: personalize_dictionary

## About this task

By default, fields are created without this constraint. A field can have unique values only if there aren't already duplicate values in the database for that field. The system doesn't allow you to make a field unique while there
are duplicate values in the table.

The system also doesn't allow you to add a unique index if a non-unique index already exists. In this scenario, you can't select the Unique check box on the form; instead, the system directs you to the
Tables \& Columns module, so you can drop the non-unique index, and then create the unique index.

## Procedure

1. Verify that no records in the table for the field have values, or that they all have the same value.
2. Right-click the field label in the form and select Configure Dictionary.
3. [Configure the form](https://servicenow-prod.fluidtopics.net/1phGIP6~lfwMUKKczOxN0Q#configure-form-layout "Administrators or users with the personalize_form role can configure the form and related list layout.") to add the Unique field if it does not already appear.
4. Select the Unique check box.
5. Update.
**Related concepts**   

* [Configuring the form layout](https://servicenow-prod.fluidtopics.net/1phGIP6~lfwMUKKczOxN0Q#configure-form-layout "Administrators or users with the personalize_form role can configure the form and related list layout.")