Mailchimp List Subscribe Form

Use the Mailchimp List Subscribe plugin to quickly add a Mailchimp signup form block, widget, or shortcode to your WordPress site.

After installation, if you already have a Mailchimp account, you’ll log in with that account and then proceed to configure settings.

If you don’t have an account, you can create one directly in the plugin. After entering in all your personal details, you’ll need to activate your account via an email that will be sent to you. Once done, you’ll proceed to configure settings.

On the settings screen, you’ll select your Mailchimp list, choose merge fields and groups, and configure other options. Once done, you can now add the block, widget, or shortcode to your site. Typically, installation and setup will take about 5-10 minutes, and absolutely everything can be done via the WordPress Setting GUI, with no file editing at all.

WordPress.com compatibility is limited to Business tier users only. How to add a signup form if you have a WordPress.com site.

Access Token Encryption

Starting in version 1.6.0, authentication has changed to use OAuth. As part of this process, we retrieve an access token that can be used to make API requests. To provide a high-level of security, this access token is encrypted before being stored in the WordPress database. In order to ensure this access token can be decrypted when used, the plugin relies on certain security constants that should remain unchanged.

With no additional configuration, we use the standard LOGGED_IN_KEY and LOGGED_IN_SALT constants that are normally set in your site’s wp-config.php file. Some sites make use of security plugins that rotate these constants on a periodic basis. When this happens, we won’t be able to decrypt the access token and you’ll need to reconnect your Mailchimp account to generate a new access token.

To prevent such issues, it is recommended to define two additional constants in your site’s wp-config.php file: MAILCHIMP_SF_ENCRYPTION_KEY and MAILCHIMP_SF_ENCRYPTION_SALT. These constants should consist of a combination of characters, preferably at least 32 characters long. Once set, these values should not be changed. For strong values, you can copy some of the values from here and use them. You’ll end up with additional code like the following in your wp-config.php file:

define( 'MAILCHIMP_SF_ENCRYPTION_KEY', 'put your unique phrase here' );
define( 'MAILCHIMP_SF_ENCRYPTION_SALT', 'put your unique phrase here' );

If these constants are added after you’ve already authenticated with Mailchimp, you will need to reconnect your account. To avoid this, you can copy the values from LOGGED_IN_KEY and LOGGED_IN_SALT (if they exist) to MAILCHIMP_SF_ENCRYPTION_KEY and MAILCHIMP_SF_ENCRYPTION_SALT respectively.

Upgrading

If you are upgrading to version 1.2.1 and you used the widget in your sidebar previously, all you need to do is drag the Mailchimp Widget back into the sidebar, visit the Mailchimp settings page (which will have maintained your prior settings), click the “Update List” button, and you’re done!

Advanced

If you have a custom-coded sidebar or something that prevents enabling widgets through the WordPress GUI, complete these steps instead.

WordPress v2.8 or higher:
[mailchimpsf_form]

If you are adding it inside a php code block, add this:

 mailchimp_sf_signup_form(); 

Or, if you are adding it within HTML, use this:

<?php mailchimp_sf_signup_form(); ?>

Where ever you want it to show up.

1.6.0 – 2024-09-24

Note this version increased the WordPress minimum version to 6.1 and the PHP minimum version to 7.0.

• Added: Mailchimp List Subscribe Form custom block (props @nateconley, @dkotter, @jeffpaul via #35, #38).
• Added: PHP 8.3 compatibility and minimum PHP version of 7.0 (props @nateconley, @jeffpaul, @dkotter via #26).
• Added: WordPress 6.5 compatibility (props @nateconley, @dkotter, @jeffpaul via #27).
• Added: OAuth authentication for connecting a Mailchimp account with WordPress (props @iamdharmesh, @dkotter, @jeffpaul via #47, #48, #50, #52).
• Added: New user signup flow, allowing users to sign up for a Mailchimp account from within the plugin (props @iamdharmesh, @dkotter, @jeffpaul via #51).
• Added: Created a LICENSE.md file and sets the license in the plugin to GPL-2.0-or-later (props @jeffpaul, @dkotter via #14).
• Added: Plugin icon and banner assets (props @eddieshrake, @jeffpaul, @dkotter via #28).
• Changed: Bump WordPress “tested up to” version 6.6 (props @qasumitbagthariya, @vikrampm1, @jeffpaul via #43).
• Changed: Ensure the signup form is only visible when a list is selected in the settings (props @iamdharmesh, @dkotter, @qasumitbagthariya via #54).
• Changed: Moved settings page and link to top-level WP Admin menu item (props @nateconley, @dkotter, @jeffpaul via #29, #33).
• Changed: Admin styles to match updated Mailchimp brand guidelines (props @nateconley, @dkotter, @jeffpaul, @eddieshrake via #31).
• Changed: Replaced references of MailChimp to Mailchimp except where those references are explicitly functional code (to limit the additional class/function updates needed) (props @jeffpaul, @dkotter via #14).
• Changed: Updated readme.txt and mailchimp.php header values to the WP.org standards (props @jeffpaul, @dkotter via #14).
• Changed: Moved screenshots into a new .wordpress-org directory (props @jeffpaul, @dkotter via #14).
• Changed: Moved translations to GlotPress (props @nateconley, @dkotter, @jeffpaul via #39).
• Deprecated: Function mailchimpSF_signup_form deprecated in favor of mailchimp_sf_signup_form (props @nateconley, @dkotter via #24).
• Deprecated: jQuery scrollTo (props @nateconley, @dkotter, @jeffpaul via #27).
• Removed: Support for WordPress < 6.1.1 (props @nateconley, @dkotter, @jeffpaul via #27).
• Removed: Polyfills for WordPress < 2.8.0 (props @nateconley, @dkotter, @jeffpaul via #27).
• Removed: Monkey Rewards integration (props @nateconley, @dkotter, @jeffpaul via #30).
• Removed: IE-specific admin stylesheet (props @nateconley, @dkotter, @jeffpaul, @eddieshrake via #31).
• Fixed: Formatting from linting checks (props @nateconley, @dkotter via #23).
• Fixed: Datepicker display on frontend (props @nateconley, @dkotter, @jeffpaul via #25).
• Fixed: Accessibility for admin settings page (props @nateconley, @dkotter, @jeffpaul, @eddieshrake via #31).
• Fixed: Properly handle the scenario where a non-valid list is updated (props @dkotter, @qasumitbagthariya, @nateconley, @vikrampm1 via #40).
• Fixed: Ensure the custom block and shortcode both have consistent spacing (props @dkotter, @qasumitbagthariya, @nateconley, @vikrampm1 via #41).
• Fixed: Address some PHP warnings when a form submission happens (props @iamdharmesh, @dkotter, @qasumitbagthariya via #54).

1.5.8 – 2022-09-26

• Changed: Updated readme.txt link.
• **Fixed:* PHP warning for merge tags.
• Fixed: Double slashes on resources being loaded.

View historical changelog details here.

This section describes how to install the plugin and get started using it.

Version 2.8+

1. Unzip our archive and upload the entire mailchimp directory to your /wp-content/plugins/ directory.
2. Activate the plugin through the Plugins menu in WordPress.
3. Navigate to the Mailchimp menu.
4. Click the Log in button and proceed through the OAuth flow, logging in to your Mailchimp account and authorizing the application.
5. Select the list where you want to send new Mailchimp subscribers.
6. Optional: Turn Merge Fields and Groups on or off. Navigate to Appearance, and click Widgets. Drag the Mailchimp Widget into one of your Widget Areas.
7. Optional: adjust frontend site display with available CSS options.