Oct 012015
WordPress Plugin Name: MC4WP: Mailchimp for WordPress
Plugin URL:https://wordpress.org/plugins/mailchimp-for-wp/

Plugin Author: ibericode
WordPress profile: ibericode
Plugin version: 4.9.13
Last updated: June 18, 2024 (4 weeks ago)
Tested up to (WP version): WP 6.5.5
Downloaded: 0
Rating: 5 (out of 5)


Allowing your visitors to subscribe to your newsletter should be easy. With this plugin, it finally is.

This plugins helps you grow your email list in Mailchimp. You can use it to create good looking and accessible sign-up forms or integrate with any other existing form on your WordPress site, like your contact, comment or checkout form.

Some (but not all) features

  • Connect with your Mailchimp account in seconds.

  • Sign-up forms which are good looking, user-friendly and mobile optimized. You have complete control over the form fields and can build your forms using native HTML.

  • Seamless integration with the following plugins:

    • WordPress Comment Form
    • WordPress Registration Form
    • Contact Form 7
    • WooCommerce
    • Gravity Forms
    • Ninja Forms 3
    • WPForms
    • BuddyPress
    • MemberPress
    • Events Manager
    • Easy Digital Downloads
    • Give
    • UltimateMember
    • HTML Forms
    • AffiliateWP
  • Is the plugin you want to integrate with not listed above? You can probably still use our custom integration feature. Alternatively, the plugin comes with a PHP API to programmatically add a new subscriber to Mailchimp.

  • Mailchimp for WordPress Premium: Send your WooCommerce orders to Mailchimp so you can see exactly what each subscriber purchased and how much revenue your email campaigns are generating.

  • A multitude of available add-on plugins and integrations:

  • Well documented through our knowledge base.

  • Developer friendly. For some inspiration, check out our repository of example code snippets.

  • Ready for PHP 8.4, but backwards-compatible all the way down to PHP 5.6.

What is Mailchimp?

Mailchimp is a newsletter service that allows you to send out email campaigns to a list of email subscribers. It is free for lists with up to 500 email subscribers, which is why it is the newsletter-service of choice for thousands of small businesses across the globe.

If you are not yet using Mailchimp, creating an account is 100% free and only takes you about 30 seconds.


If you need some help in setting up the plugin, you have various options:


You can help translate this plugin into your language using your WordPress.org account.


This plugin is being developed on GitHub. If you want to collaborate, please look at ibericode/mailchimp-for-wordpress.

Customizing the plugin

The plugin provides various filter and action hooks that allow you to modify or extend the default behavior. We’re also maintaining a collection of sample code snippets.


Where can I find my Mailchimp API key?

You can find your API key here

How to display a form in posts or pages?

Use the [mc4wp_form] shortcode or the Gutenberg block.

How to display a form in widget areas like the sidebar or footer?

Go to Appearance > Widgets and use the Mailchimp for WP Form widget that comes with the plugin.

How to add a sign-up checkbox to my Contact Form 7 form?

Use the following shortcode in your CF7 form to display a newsletter sign-up checkbox.

[mc4wp_checkbox "Subscribe to our newsletter?"]

Our knowledge base has more information on connecting Contact Form 7 and Mailchimp.

The form shows a success message but subscribers are not added to my list(s)?

If the form shows a success message, there is no doubt that the sign-up request succeeded. Mailchimp could have a slight delay sending the confirmation email though. Please check again in a few minutes (sometimes hours) and don’t forget to check your junk folder too.

When you have double opt-in disabled, new subscribers will be seen as imports by Mailchimp. They will not show up in your daily digest emails or statistics. We always recommend leaving double opt-in enabled.

How can I style the sign-up form?

You can use custom CSS to style the sign-up form if you do not like the themes that come with the plugin. The following selectors can be used to target the various form elements.

.mc4wp-form { ... } /* the form element */
.mc4wp-form p { ... } /* form paragraphs */
.mc4wp-form label { ... } /* labels */
.mc4wp-form input { ... } /* input fields */
.mc4wp-form input[type="checkbox"] { ... } /* checkboxes */
.mc4wp-form input[type="submit"] { ... } /* submit button */
.mc4wp-alert { ... } /* success & error messages */
.mc4wp-success { ... } /* success message */
.mc4wp-error { ... } /* error messages */

You can add your custom CSS to your theme stylesheet or (easier) by using a plugin like Simple Custom CSS

How do I show a sign-up form in a pop-up?

We recommend the Boxzilla pop-up plugin for this. You can use the form shortcode in your pop-up box to show a sign-up form.

How do I subscribe from my WooCommerce checkout form?

You can use our WooCommerce integration for that. How to subscribe to Mailchimp from the WooCommerce checkout form.

How to connect my WooCommerce store with Mailchimp?

You can find instructions for connecting your WooCommerce store with Mailchimp on our website.

I’m getting an “HTTP Error” when trying to connect to Mailchimp.

the “HTTP Error” type is usually because of a firewall configuration issue or outdated software on your web server.

Please contact your webhost and ask them to check the following:

  • Whether remote HTTP requests to https://api.mailchimp.com are allowed.
  • Whether cURL and the PHP-cURL extension are installed and updated to a recent version.

My question is not listed here.

Please search through our knowledge base.


  1. Example sign-up form in the TwentyTwenty theme.

    Example sign-up form in the TwentyTwenty theme.

  2. Example sign-up integration with a contact form.

    Example sign-up integration with a contact form.

  3. Settings page to connect with your Mailchimp account.

    Settings page to connect with your Mailchimp account.

  4. Overview of sign-up integrations.

    Overview of sign-up integrations.

  5. Overview of sign-up forms.

    Overview of sign-up forms.

  6. Settings page to configure an integration.

    Settings page to configure an integration.

  7. Page where you edit your sign-up forms.

    Page where you edit your sign-up forms.

  8. Page where you modify your form messages.

    Page where you modify your form messages.

  9. Settings page for e-commerce integration with Mailchimp. Requires <a href="https://www.mc4wp.com/">Mailchimp for WordPress Premium</a>.

    Settings page for e-commerce integration with Mailchimp. Requires Mailchimp for WordPress Premium.

Other notes:

Latest Change log entry:

  • Fix issue with Composer classmap throwing a fatal error when an older version of Composer is already loaded.


email, form, mailchimp, newsletter, subscribe

+ Jason's Comments

I use this plugin to integrate with Contact Form 7, giving people the option to subscribe to the Mailchimp mail-list, when filling out a form. If you have more than one list and more than one CF7 form, you need to read Knowlegde Base for Mailchimp plugin to know how to assign the sign up checkbox for a specific mail-list.