### [How to Set Minimum Amount for a Price Field](https://wpforms.com/developers/how-to-set-minimum-amount-for-a-price-field/)

**Published:** August 17, 2021
**Author:** Editorial Team

**Excerpt:** This tutorial will show you how to set a minimum amount on a user-defined price field using PHP.

**Content:**

## Introduction

Would you like to set a minimum amount for a price field on your WPForms? Using a small PHP snippet you can easily set a minimum amount for the **Single Item** price field that is **User Defined**. In this tutorial, we’ll walk you through each step on how to achieve this.

## Creating the form

First, you’ll need to create a form and add a **Single Item** price field to the form. Once you’ve added the field, please make sure that the **Item Type** is set to **User Defined**.

If you need any assistance in setting up a form with the **Single Item** field, [please check out this article](https://wpforms.com/how-to-add-optional-payment-to-your-wordpress-forms/ "How to Add Optional Payment to Your WordPress Forms").

![create a new form a, add a single item price field to your form and set the item type to user defined](https://wpforms.com/wp-content/uploads/2021/08/wpforms-user-defined-price-field.jpg)

## Adding the CSS class

Next, we’re going to add a CSS class to this field so that it will trigger the snippet to check for the minimum amount we require.

To add a CSS class name to a form field, select the **Single Item** field and click the **Advanced** tab. Inside the **CSS Classes**, enter the `set-minimum` and save the form.

![add the css class name to the single item field](https://wpforms.com/wp-content/uploads/2021/08/wpforms-add-class-name.jpg)

## Adding the snippet to set a minimum amount

In this final step, you’ll need to add the snippet to your site. If you need help in adding snippets to your site, [please see this tutorial](https://wpforms.com/developers/how-to-add-custom-php-or-javascript-for-wpforms/ "How to Add Custom PHP or JavaScript for WPForms").

```

/**
 * Set a minimum amount price field.
 *
 * @link https://wpforms.com/developers/how-to-set-minimum-amount-for-a-price-field/
 */

function wpf_set_minimum_amount_input( $field_id, $field_submit, $form_data ) {
 
    // This snippet will run for all forms
    $form_id = $form_data[ 'id' ];
 
    // And it will run for all fields with the CSS class of set-minimum
    $fields  = $form_data[ 'fields' ];

	// Define your minimum amount here.
	$minimum_amount = 5;
 
    // Check if field has custom CSS class configured
    if ( !empty( $fields[ $field_id ][ 'css' ] ) ) {
 
        $classes = explode( ' ', $fields[$field_id][ 'css' ] );
 
        if ( in_array( 'set-minimum', $classes ) ) {
 
            if ( $minimum_amount > (float) wpforms_sanitize_amount( $field_submit ) ) {
 
                wpforms()->process->errors[ $form_id ][ $field_id ] = __( 'Minimum amount is $' . $minimum_amount . '.', 'plugin-domain' );
 
                return;
            }
        }
    }
}
add_action( 'wpforms_process_validate_payment-single', 'wpf_set_minimum_amount_input', 10, 3 );
```

This snippet will automatically run for all forms but will only run on the fields that have the CSS class name **set-minimum**. If the amount entered doesn’t meet the minimum it will produce an error when the form is submitted.

![now there is a minimum amount error when the form is submitted.](https://wpforms.com/wp-content/uploads/2021/08/wpforms-error-minimum-not-met.jpg)

And that’s all you need! Would you like to know how to hide this amount from the email notifications? Check out our tutorial on [How to Hide the Item Price Value in the Email Notifications](https://wpforms.com/developers/how-to-hide-the-item-price-value-in-the-email-notifications/ "How to Hide the Item Price Value in the Email Notifications").

## FAQ

#### Q: Why isn’t this working for my site?

**A: **If this isn’t error isn’t stopping your form submission, double-check that you have entered the CSS class name in the correct field.****

![add the css class name to the single item field](https://wpforms.com/wp-content/uploads/2021/08/wpforms-add-class-name.jpg)

#### Q: How do I set a maximum amount?

**A:** To use a similar snippet to set a maximum amount, first you’ll need to update the **CSS Classes** name to `set-maximum` in the same manor you did in the previous step above.

Then, just add this snippet to your site.

```

/**
 * Set a maximum amount price field.
 *
 * @link https://wpforms.com/developers/how-to-set-minimum-amount-for-a-price-field/
 */
 
function wpf_set_maximum_amount_input( $field_id, $field_submit, $form_data ) {
 
    // This snippet will run for all forms
    $form_id = $form_data[ 'id' ];
 
    // And it will run for all fields with the CSS class of set-minimum
    $fields  = $form_data[ 'fields' ];

	// Define your minimum amount here.
	$maximum_amount = 5000;
 
    // Check if field has custom CSS class configured
    if ( !empty( $fields[ $field_id ][ 'css' ] ) ) {
 
        $classes = explode( ' ', $fields[ $field_id ][ 'css' ] );
 
        if ( in_array( 'set-maximum', $classes ) ) {
 
            if ( $maximum_amount < (float) wpforms_sanitize_amount( $field_submit ) ) {
 
                wpforms()->process->errors[ $form_id ][ $field_id ] = __( 'Maximum amount is $' . $maximum_amount . '.', 'plugin-domain' );
 
                return;
            }
        }
    }
}
add_action( 'wpforms_process_validate_payment-single', 'wpf_set_maximum_amount_input', 10, 3 );

```

**Categories:** Tutorials

**Tags:** PHP

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