### [Sending the Entry ID to Mailchimp](https://wpforms.com/developers/how-to-send-the-entry-id-through-to-mailchimp/)

**Published:** April 29, 2021
**Author:** David Ozokoye

**Excerpt:** This tutorial will walk you through how to pass through the entry ID to Mailchimp lists using a small PHP snippet. 

**Content:**

Would you like to send the entry ID to Mailchimp? It’s an easy way to track and find specific users who sign up for your newsletter by simply searching for the entry ID number.

In this tutorial, we’ll walk you through each step on how to send this ID number to Mailchimp when users complete your forms.

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## Creating the Custom Field in Mailchimp

First, you’ll want to create a custom field in Mailchimp that will store this ID number. To do this, you can [follow along with the steps in their guide](https://mailchimp.com/help/manage-audience-signup-form-fields/ "Manage Audience and Signup Form Fields").

For our form, we created a form inside Mailchimp that has the **First Name**, **Last Name**, **Email Address**, and a simple **Text** field.

The Settings for this field will have the **Field Label** as **Entry ID** and the **Field Tag** as **ENTRY\_ID**.

Once you’ve saved the field to your form, your **All Contacts** page will show the column for this field. This is where we will store the entry ID when the form is submitted.

![add your custom field to your mailchimp form](https://wpforms.com/wp-content/uploads/2021/04/wpforms-add-custom-field-to-mailchimp.jpg)## Creating Your Form

To do so, [create a new form](https://wpforms.com/docs/creating-first-form/) or edit an existing one to access the form builder. In the form builder, go ahead and add the fields you’d like to your form. For our example, we’ve added the Name and Email fields to our form.

If you need help in creating your form, [please see this tutorial](https://wpforms.com/docs/creating-first-form/ "Creating Your First Form").

![create your form with your desired fields](https://wpforms.com/wp-content/uploads/2024/12/newsletter-opt-in-form.png)## Connecting Your Form to Mailchimp

**Note:** You’ll need to install and configure the Mailchimp addon on your site to continue. See our tutorial on [setting up the Mailchimp addon](https://wpforms.com/docs/install-use-mailchimp-addon-wpforms/) for more details.

Now, it’s time to connect your form to your Mailchimp account. To do so, go to **Marketing » Mailchimp** and click the **Add New Connection** button.

![Add New Mailchimp connection](https://wpforms.com/wp-content/uploads/2024/12/add-new-connection.png)Then, proceed to connect your account and map your specify the action to perform for each form submission.

![Mapping fields for Mailchimp integration](https://wpforms.com/wp-content/uploads/2024/12/map-fields-1.png)Once you’ve set up your connection and mapped your fields, you are ready for the next step!

## Adding the Code to Send the Entry ID to Mailchimp

Now it’s time to add the snippet that will send through this ID when the form is processed and the subscriber is added to the Mailchimp list.

If you need help in adding code 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").

```

/** Send through entry ID from WPForms to Mailchimp
 *
 *  @link   https://wpforms.com/developers/how-to-send-the-entry-id-through-to-mailchimp/
**/

function wpf_dev_mailchimp_provider_process_action_subscribe_request_data( $data, $fields, $form_data, $entry_id ) {

    if ( empty( $entry_id ) ) {
      return $data;
    }

    // Change 'ENTRY_ID' to match the custom field you've created inside Mailchimp. See this doc for more details
    $data[ 'merge_fields' ][ 'ENTRY_ID' ] = absint( $entry_id );

    return $data;

}

add_action( 'wpforms_mailchimp_provider_process_action_subscribe_request_data', 'wpf_dev_mailchimp_provider_process_action_subscribe_request_data', 10, 4 );
```

If you didn’t name your custom field **ENTRY\_ID** as instructed above, be sure to update this code snippet to match the name inside this line **$data\[‘merge\_fields’\]\[‘ENTER\_CUSTOM\_FIELD\_NAME\_HERE’\]**

Now when users complete your form and you view the subscriber, you’ll see the entry ID number in the contacts list.

![now the entry id will be passed to mailchimp](https://wpforms.com/wp-content/uploads/2021/04/wpforms-add-entry-id-to-mailchimp.jpg)That’s it! You’ve now learned how to send your form entry ID to Mailchimp.

Next, would you like to create a Smart Tag for a unique ID so that you can use it in other areas of your form? Take a look at our article on [creating a unique ID for each form entry](https://wpforms.com/developers/how-to-create-a-unique-id-for-each-form-entry/ "How to Create a Unique ID for Each Form Entry").

**Categories:** Tutorials

**Tags:** Mailchimp, PHP

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