Mailchimp Custom Fields: Map CF7 Form Data to Merge Tags

Mailchimp custom fields let you send additional subscriber data — like phone numbers, company names, and addresses — from your Contact Form 7 forms directly into Mailchimp. In other words, instead of capturing only an email address, you can map any form field to a corresponding Mailchimp merge tag and build richer subscriber profiles.

Additionally, this feature is built into the Contact Form 7 Mailchimp Extension at no extra cost. The Mailchimp custom fields mapping is available in the free version and works with any Contact Form 7 form.

Furthermore, this guide explains what Mailchimp custom fields and merge tags are, how to create them in Mailchimp, and how to map your Contact Form 7 fields to send data into them.

What Are Mailchimp Custom Fields?

Every Mailchimp audience has a set of fields that store subscriber information. By default, Mailchimp creates two fields: Email Address and a Name field. However, you can add as many Mailchimp custom fields as you need — phone, company, city, job title, birthday, or any other data point relevant to your business.

Specifically, each custom field in Mailchimp has two identifiers:

• Field label — the human-readable name you see in the Mailchimp dashboard (e.g., “Phone Number”).
• Merge tag — the short code used by the API and email templates (e.g., PHONE or MMERGE3).

In fact, merge tags are what the Contact Form 7 Mailchimp Extension uses to map your form data to the right fields in Mailchimp.

How Mailchimp Custom Fields Work with Contact Form 7

The mapping process connects a Contact Form 7 mail-tag to a Mailchimp merge tag. Specifically, the workflow is:

1. Visitor submits a form with fields like name, email, phone, and company.
2. Contact Form 7 processes the submission and makes the field values available as mail-tags (e.g., [your-name], [your-email], [your-phone]).
3. The plugin reads the field mapping you configured in the Mailchimp tab.
4. Each mail-tag value is sent to the corresponding Mailchimp merge tag via the API.
5. Mailchimp stores the data in the subscriber’s profile under the matching custom field.

As a result, your Mailchimp audience gets fully populated subscriber profiles instead of just email addresses.

Creating Mailchimp Custom Fields

Before mapping fields in the plugin, you need to create the corresponding custom fields in Mailchimp. Moreover, the fields must exist in your audience before the API can accept data for them.

1. Log in to Mailchimp at mailchimp.com.
2. Click Audience in the left navigation.
3. Select Settings from the “Manage Audience” dropdown.
4. Click Audience fields and *|MERGE|* tags — this shows all existing fields and their merge tags.
5. Click Add A Field and choose the field type (text, number, date, phone, address, etc.).
6. Name the field and note the merge tag Mailchimp assigns (e.g., MMERGE3 or a custom tag you define).

In addition, you can rename the default merge tags. For example, change MMERGE3 to PHONE for easier identification. The merge tag is what you enter in the plugin’s field mapping.

Mapping Mailchimp Custom Fields in WordPress

After creating your Mailchimp custom fields, follow these steps to map them in the plugin:

1. Open your WordPress admin and navigate to Contact > Contact Forms.
2. Edit the form you want to connect to Mailchimp.
3. Click the Mailchimp tab in the form editor.
4. Make sure your Mailchimp API key is entered and your audience is selected.
5. Find the field mapping section — you will see two columns: CF7 mail-tags on the left and Mailchimp merge tags on the right.
6. Enter the mappings — for example, [your-phone] on the left and PHONE on the right.
7. Click Save and submit a test entry to verify.

Consequently, every form submission sends the mapped data to the correct Mailchimp custom fields along with the email address.

Common Field Mapping Examples

The following table shows typical mappings between Contact Form 7 mail-tags and Mailchimp merge tags:

CF7 Mail-Tag	Mailchimp Merge Tag	Data
[your-name]	FNAME	First name
[your-last-name]	LNAME	Last name
[your-phone]	PHONE	Phone number
[your-company]	COMPANY	Company name
[your-city]	CITY	City
[your-birthday]	BIRTHDAY	Date of birth

Specifically, the CF7 mail-tags must match the field names in your Contact Form 7 form template. The Mailchimp merge tags must match the tags shown in your Mailchimp audience field settings.

First Name and Last Name Mapping

Mailchimp has two default name merge tags: FNAME for first name and LNAME for last name. However, many Contact Form 7 forms use a single “Your Name” field that captures the full name.

In this case, map the single name field to FNAME. Mailchimp stores the full name in the first name field. Alternatively, if you want to split the name:

1. Create two separate fields in your CF7 form — [text* your-first-name] and [text your-last-name].
2. Map them individually — [your-first-name] to FNAME and [your-last-name] to LNAME.

As a result, Mailchimp can personalize emails with just the first name, which looks more natural than using the full name.

Common Mailchimp Custom Fields Issues

Data not appearing in Mailchimp

If custom field data is not showing up in subscriber profiles, check the merge tag spelling. Specifically, the merge tag in the plugin must exactly match the merge tag in Mailchimp — including capitalization. In fact, phone and PHONE are treated as different tags.

Field type mismatch

If you created a “Number” field in Mailchimp but your CF7 form sends text, Mailchimp may reject the data silently. Consequently, make sure the data type in your form matches the field type in Mailchimp. Use text fields in Mailchimp for maximum flexibility.

Merge tag not recognized

Custom fields must be created in Mailchimp before you can map data to them. Moreover, if you recently created a field, the plugin may need a fresh API call to pick it up. Save the form settings again to refresh the connection.

Next Steps

After configuring your Mailchimp custom fields, you may also want to review these guides:

• Mailchimp API key setup — make sure your credentials are configured correctly.
• Mailchimp List ID guide — target specific audiences by ID.
• Add a Mailchimp opt-in checkbox — let visitors choose whether to subscribe.

Additionally, if you need help with Mailchimp custom fields or any other aspect of the plugin, contact us directly.