Title: MailChimp API Error Last modified: June 2, 2017 --- # MailChimp API Error * Resolved [Winework](https://wordpress.org/support/users/winework/) * (@winework) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/) * Hi, I have created some extra fields in the default user registration form and he registration process works fine. However, when I activate the Mailchimp for WordPress plug-in, so that new registrants are added to my Mailchimp list, one field is being rejected by the Mailchimp API. * **Debug Log** [2016-07-09 16:49:54] ERROR: Registration Form > MailChimp API Error: MMERGE9 must be provided – Please enter a value * **Form Field Info** Name: MC4WP-MMERGE9 Type: Dropdown Label: Business Type/ Consumer, Retailer, Hospitality, Marketing, Wine Trade, Producer, Media/Publication, Other (includes dropdown options) * **Mailchimp Field Info** Name: MMERGE9 Type: Dropdown Label: Business Type Business Type Options: Consumer, Retailer, Hospitality, Marketing, Wine Trade, Producer, Media/Publication, Other * Any advice gratefully received! * Colin Ford [http://www.winework.com](http://www.winework.com) * [https://wordpress.org/plugins/mailchimp-for-wp/](https://wordpress.org/plugins/mailchimp-for-wp/) Viewing 6 replies - 1 through 6 (of 6 total) * Plugin Contributor [Harish Chouhan](https://wordpress.org/support/users/hchouhan/) * (@hchouhan) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-7557643) * Hello Colin, * The error logged is because a field “MMERGE9” is set as mandatory in your MailChimp list but is not provided when the registration form is submitted. To fix this make sure the field values of “MMERGE9” are same in your form as they are in your MailChimp list. Also make sure to test the registration form with a value selected for this field. If this does not work, I would recommend unchecking that field as “Mandatory” in your MailChimp list. * Thread Starter [Winework](https://wordpress.org/support/users/winework/) * (@winework) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-7557687) * Hello Harish, * Thank you for your suggestions. * I am using the free version of mp4wp & I have a subscription form on the site that uses mc4wp and it works perfectly. [http://www.winework.com/subscribe/](http://www.winework.com/subscribe/) * After hours working on this I have managed to get my site registration and Mailchimp signup to work concurrently. Taking the “mandatory” setting off any of the Mailchimp fields, as you suggested, helped. * Now my problem is that although the new user is created in Mailchimp when registering, the only field that is being populated in Mailchimp is the email field. * mc4wp is not logging any errors. * All the other fields, named as follows are shown in the user’s site profile but not in Mailchimp. * **Fields** EMAIL” (required) FIRSTNAME LASTNAME MC4WP-MMERGE5 (Job Title) MC4WP- MMERGE4 (Business Name) MC4WP-MMERGE9 (Business Type) MC4WP-MMERGE7 (Country) MC4WP-MMERGE3 (Region) * I suspect that it is because the native WP fields Firstname and Lastname are not prefixed with “MC4WP-“. * Any clues on how to proceed? * Colin winework.com * Plugin Contributor [Harish Chouhan](https://wordpress.org/support/users/hchouhan/) * (@hchouhan) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-7557698) * Hello Colin, * Are you by any chance using custom registration form? * Also, please note that we have another add-on “[MailChimp Sync](https://wordpress.org/plugins/mailchimp-sync/)” that can be used to sync your data from user table to your MailChimp list. This plugin does the sync in the background so you won’t have to edit your registration forms. * Thread Starter [Winework](https://wordpress.org/support/users/winework/) * (@winework) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-7557704) * Hi Harish, * Thank you for your response. Yes, I have been using a custom registration form. I’ve installed Mailchimp-Sync as you advised too. But I’m still not getting the custom fields populated in Mailchimp, so I have uninstalled the custom registration form plugin (Cimy) and am starting again from scratch. * Here is what I want to achieve. Can advise me if it can be done using your plugin? * 1) At registration, I want to collect the following fields of customer meta… * First Name [text]; required Last Name [text] Job Title [text] Business Name [ text] Business Type [drop-down]; required Country [drop-down]; required Region[ drop-down]; required * 2) If the user selects the ‘add to mail list’ checkbox when registering, then the information above is also sent to Mailchimp and they are automatically subscribed to our mail list. * 3) If the user un-checks the checkbox when registering, then their information is NOT sent to Mailchimp, but they are registered on our site. * Seems that Mailchimp-Sync would be ideal, if I could get it to populate the custom fields in Mailchimp. (Yes, I have mapped the fields in MC-Sync.) * Please tell me if I’m using the right tool for the job in mc4wp! * Thanks again, * Colin winework.com * Plugin Contributor [Lap](https://wordpress.org/support/users/lapzor/) * (@lapzor) * [9 years, 10 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-7557706) * Hi, * Either way it should work if set-up correctly. * Is it an option to make MMERGE9 a normal text field instead of drop-down on the MailChimp.com side (leave it a drop-down on WordPress side) and make it not required in MailChimp. Then you can see if it at least receives any data or if it still stays blank. * Plugin Contributor [Lap](https://wordpress.org/support/users/lapzor/) * (@lapzor) * [8 years, 12 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-9190180) * Since there have been no replies to this topic for awhile I will now close this ticket as resolved. If you still have a problem or you have a similar problem as posted above, please open a NEW topic. Thank you! Viewing 6 replies - 1 through 6 (of 6 total) The topic ‘MailChimp API Error’ is closed to new replies. * ![](https://ps.w.org/mailchimp-for-wp/assets/icon-256x256.png?rev=1224577) * [MC4WP: Mailchimp for WordPress](https://wordpress.org/plugins/mailchimp-for-wp/) * [Frequently Asked Questions](https://wordpress.org/plugins/mailchimp-for-wp/#faq) * [Support Threads](https://wordpress.org/support/plugin/mailchimp-for-wp/) * [Active Topics](https://wordpress.org/support/plugin/mailchimp-for-wp/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/mailchimp-for-wp/unresolved/) * [Reviews](https://wordpress.org/support/plugin/mailchimp-for-wp/reviews/) * 6 replies * 3 participants * Last reply from: [Lap](https://wordpress.org/support/users/lapzor/) * Last activity: [8 years, 12 months ago](https://wordpress.org/support/topic/mailchimp-api-error/#post-9190180) * Status: resolved