# Custom Data Validation Add-On ¶

## Introduction ¶

> The CSV Data Validator Add-On is a premium one, you can buy it on our landing page. Thank you!

So useful if you want to validate coupons, license keys, company numbers, IDs, specific email addresses, etc. If the entered value matches one defined in the CSV file, the form will be sent, if not, a custom validation message will be displayed on the validated field.

##### For a Specific Field and for All Fields ¶

You can create a custom validation that can only be used on a specific Field. But also, you can create validation for multiple fields of the same form. There are no limits.

##### Use a custom validation message on each field ¶

You can define the error message that you want to show when the value entered in the field does not match any of the values in the uploaded CSV file.

## Install CSV Data Validator Add-On ¶

The CSV Data Validator Add-On installing process is very simple, same to any other Add-On. To install the CSV Data Validator Add-On follow the documentation to install an Add-On from the Add-On Manager.

## Create a CSV Data Validation ¶

To create a custom validation, you must perform the following steps:

1. Go to the Add-ons Manager and click on CSV Data Validator.
2. Click on the Set Up a Form button.
3. A form used to configure the validation will appear.
   - Form: Select the form to validate.
   - Status: Can be:
     - On: Enable validation
     - Off: Disable validation
   - Fields: It's composed of:
     - Field: Choose the field to be validated.
     - Field Message: The custom error message if the value entered by the user doesn’t matches to any of the defined values in the CSV file.
     - Field Values: A File Upload field where you must upload your CSV file. The CSV file should only contain one column that lists all valid values for the field.
4. Click Create