Mailchimp Default Audience Fields Explained

The 5 Default Fields, at a Glance

Use this table to map the default audience fields to your Contact Form 7 fields when you connect with Chimpmatic. The fields exist in the audience database from the moment the audience is created; you never create them manually.

Mailchimp’s own developer documentation confirms the set:

Merge fields with the tags *|FNAME|*, *|LNAME|*, *|ADDRESS|*, and *|PHONE|* are present by default when an audience is created.

Combined with the required Email Address field, that is five fields total, on every plan, whether the audience was created in the web app or through the API.

Each Field, Explained

Email Address (*|EMAIL|*)

The only field that is always required, and the audience’s primary key. Every subscriber row is uniquely identified by email address; Mailchimp does not expose any other stable identifier. This field cannot be deleted, renamed, or made optional, and two consequences follow directly from it being the key:

• If a subscriber changes their email address, Mailchimp treats them as a different subscriber. Tags, segment memberships, and campaign history do not follow the person; there is no built-in merge that preserves history.
• You cannot have two subscribers with the same email in one audience. Adding a duplicate either updates the existing record or is rejected by the API, depending on how you import.

This is also why GDPR consent flows tie consent to the email address, and why Chimpmatic validates the email before any other field: without it there is no row to write to.

First Name (*|FNAME|*) and Last Name (*|LNAME|*)

Plain text fields, visible on the signup form, never required. FNAME is the most-used merge tag in email marketing because it powers the standard greeting pattern, Hello *|FNAME|*. Treat both as unreliable data: subscribers skip them freely, which is exactly why default merge values exist (covered below).

Address (*|ADDRESS|*)

A compound field that stores six sub-values under one merge tag: address line 1, address line 2, city, state/province, zip/postal code, and country. Hidden from the signup form by default. Two practical notes that the basic tutorials skip:

• Populated via the API, it requires addr1, city, state, and zip as separate values (addr2 and country are optional). You cannot write a single free-text string into it.
• In a campaign, *|ADDRESS|* renders the entire formatted address block, newlines included. If you want just the city, use the sub-field token *|ADDRESS:CITY|*; the others are :ADDR1, :ADDR2, :STATE, :ZIP, and :COUNTRY.

Phone Number (*|PHONE|*)

Hidden by default, stores international or US format (configurable on the Audience Fields and Merge Tags page). Do not confuse it with the separate SMS Phone Number field, which only exists after you set up Mailchimp’s SMS Marketing program and is the one SMS campaigns actually use.

Visible vs. Hidden: The Signup Form Split

Of the five defaults, only three appear on Mailchimp’s generated signup form: Email Address, First Name, and Last Name. Address and Phone are hidden.

Hidden does not mean deleted. The Address and Phone fields exist in your audience database, can store data, can be used for segmentation, and can be populated through imports or API calls. They are simply not shown to subscribers. You can flip visibility at any time in the Form Builder or the Audience Fields and Merge Tags settings; hiding a visible field removes it from the form but keeps its data.

This split is the source of a common duplicate-field mistake: people do not see Address or Phone on the form, assume the fields do not exist, and create custom ones alongside the built-ins. Check the field list before creating anything.

Why Did Mailchimp Choose These 5 Fields?

The set is not arbitrary. Each default maps to a core email-marketing function:

• Email Address is the foundation. Campaigns, automations, segmentation, and transactional email all depend on it.
• First and Last Name enable the highest-leverage personalization pattern there is, greeting by name. They are visible but optional on purpose: requiring a name adds signup friction and costs conversions, so Mailchimp invites the data without demanding it.
• Address exists for geographic segmentation, local content, shipping, and direct mail, and it echoes the CAN-SPAM requirement that commercial email carry a valid physical mailing address (Mailchimp satisfies that at the account level in your footer). It is hidden because asking a newsletter subscriber for a mailing address would crater signups.
• Phone Number is multi-channel readiness: support workflows and, with the separate SMS field, text campaigns. Hidden for the same friction reason.

Only Email Is Truly Required

The only fields that Mailchimp requires are the email address field for email contacts, and the SMS phone number field for SMS contacts. Other fields are optional, but may be necessary for personalization, segmentation, or other features.

In practice: a contact can be created with only an email address; name, address, and phone can all stay empty; and the only exception is a field you marked as required in your own audience settings. When a web form talks to Mailchimp through the API, email is the entire minimum payload, and everything else is enrichment.

Audience Defaults: Reply-To Email, From Name, and List Name

Separate from the five subscriber fields, every audience carries audience-level defaults that describe the audience itself. These fill in the From Name, From Email, and Reply-To on every campaign you send. You will find them under Audience > Settings > Audience name and defaults:

• Audience name, the label you pick in dropdowns when sending. Mailchimp renamed “lists” to “audiences” in 2019, but the URL slug and plenty of third-party docs still say list name. Same thing.
• Default from email address, which must be on a domain you have authenticated for SPF/DKIM.
• Default from name, the sender name subscribers see.
• Default reply-to email address, where replies land when a subscriber hits Reply.

The reply-to is the one people get wrong: left unset, replies go to the campaign-sending mailbox, which often nobody reads. Point it at a real human inbox.

Does Chimpmatic care about these defaults? No. They are configured inside Mailchimp and apply to campaigns Mailchimp sends. When Chimpmatic pushes a subscriber to your audience via the API, the audience defaults are inherited automatically; there is nothing to set in WordPress.

Merge Tags: How Fields Become Personalization

Every audience field has a merge tag, a token wrapped in asterisk-and-pipe delimiters that Mailchimp replaces with the subscriber’s value at send time. Hello *|FNAME|* becomes “Hello Sarah” in Sarah’s inbox and “Hello Marcus” in Marcus’s.

The tag names follow two patterns. The five defaults use readable names: EMAIL, FNAME, LNAME, ADDRESS, PHONE. Custom fields you add later are auto-named MMERGE1, MMERGE2, MMERGE3, and so on, which is why older accounts are full of tags like *|MMERGE5|* that nobody remembers creating. You can rename them to something readable such as COMPANY under Audience > Settings > Audience fields and *|MERGE|* tags, with one caveat: Mailchimp reserves certain names, and integrations that expect the standard tags may break if you rename the defaults.

The single most useful syntax detail, and the one introductory tutorials skip: the inline fallback. If a subscriber’s field is empty, the tag renders as blank space, which reads as broken (“Hello , welcome!”). Write *|FNAME:Friend|* and Mailchimp renders “Friend” when FNAME is empty and the real name when it is not.

Two scope rules worth pinning: merge tags are case-sensitive, and they are per-audience. Each audience has its own tag set, so a tag that exists in one audience may not exist in another, and a campaign sent to the wrong audience will not resolve it.

Audience Field Limits

Audiences are limited to a maximum of 30 data fields for each contact. If you want more than 30 fields of information about your contacts, use groups to help consolidate audience fields, or use tags instead. Mailchimp accounts on a Premium plan can map up to 80 fields.

Five of the 30 are spent on the defaults, so a standard plan has room for 25 custom fields. Before you spend them, know which primitive you actually need, because Mailchimp has three that overlap in name only:

• Fields store data about a subscriber (name, company, birthday). Every subscriber has a value, possibly empty, for every field. Use a field when the data must appear in email content via a merge tag.
• Tags are labels you attach to a subscriber (“vip”, “lead-from-cf7”). A subscriber can carry many or none. Tags never render in email content and have no merge tags, despite the unfortunate naming collision; they exist for filtering and automation triggers.
• Segments are saved filters computed on demand from fields, tags, and behavior (“tagged vip, in Florida, opened in the last 30 days”). They store nothing themselves.

Categorical data (“customer vs prospect”) belongs in tags. Data you will print inside an email belongs in a field. That one rule keeps most audiences comfortably under the limit.

Available Field Types for Custom Fields

When you create a field beyond the five defaults, you pick one of these types. The type controls validation and cannot be changed after creation; a wrong choice means deleting the field (and its data, for every contact) and recreating it.

Text

Typed responses up to 255 bytes: company name, job title, preferences. First Name and Last Name use this type.

Number

Any number, such as age or employee count. Do not use it for phone numbers or zip codes; dedicated types exist for both.

Radio Buttons

Exactly one choice from a predefined list; can create groups. Ships with predefined option sets such as days of the week, US states, and countries.

Checkboxes

One or more choices; always creates a group. Audiences cap at 60 groups.

Drop Down

Exactly one choice, presented as a menu. Can also create groups.

Date

Full date, US (MM/DD/YYYY) or international (DD/MM/YYYY) format.

Birthday

Month and day only, for annual birthday automations.

Address

The same compound six-part type as the default Address field. Each line must be under 45 characters.

Zip Code

5-digit US zip codes only; use Address or Text for international postal codes.

Phone

International or US format.

Website

A full URL; generates link HTML.

Image

An image URL, for personalized images or avatars in emails.

A distinction that saves confusion later: the field type lives in the audience schema and controls what data is accepted; the merge tag is just the label campaigns use to reference the field. Adding a “Phone” field means picking the Phone type; Mailchimp then auto-assigns the tag (PHONE or MMERGE<n>). They are parallel systems, and renaming one does not touch the other.

Default Merge Tag Values: The Safety Net

Beyond the inline *|FNAME:Friend|* syntax, Mailchimp lets you set an audience-wide fallback per field, so every campaign is protected even when the author forgets the inline form:

When you use merge tags to personalize your email, it’s a good idea to set default values to display for recipients who don’t have any data for that field. For example, you could set the default value for your first name merge tag to “Friend.” When you use “Hello *|FNAME|*,” in an email, we’ll display “Hello Friend” for recipients whose first names aren’t in the system.

Two places to set them: Audience > Audience Fields and Merge Tags > Edit (the “Default merge tag value” box), or the Form Builder’s Field Settings tab. Sensible choices: “there” for First Name (so an empty field renders “Hello there”), and blank for Last Name so formal greetings never produce a fake surname. Defaults are available for every field except Email Address and Address, and Image-field defaults render as text, not an image.

Common Mistakes to Avoid

1. Treating hidden fields as nonexistent

Address and Phone are hidden, not absent. Creating duplicate custom fields for them wastes two of your 25 slots and splits your data.

2. Making too many fields required

Every required field on a signup form costs conversions. Collect the minimum at signup and enrich later through preference centers and behavior.

3. Assuming merge tags work across audiences

Tags are per-audience. Verify the tag exists in the audience you are actually sending to, especially after renaming.

4. Skipping default merge values

Any tag you use in content needs a fallback, inline or audience-level, or empty fields render as broken greetings.

5. Deleting fields instead of hiding them

Deleting a field permanently erases that field’s data for every contact. If you only want it off the form, hide it. Back up the audience before deleting anything.

6. Ignoring the 30-field limit until you hit it

Plan the schema: fields for merge-tag data, tags for labels, groups for interests. Retrofitting a 30-field audience is painful.

How This Works with Contact Form 7 and Chimpmatic

When Chimpmatic connects Contact Form 7 to Mailchimp, your CF7 fields are mapped to audience fields over the API. Knowing the default audience fields makes that mapping trivial, and it starts with an API connection: our step-by-step Mailchimp API key guide gets you connected in under 2 minutes.

A CF7 template pre-wired to the 5 defaults

Paste this into a Contact Form 7 form and every field lines up one-to-one with a Mailchimp default, so the mapping screen becomes a matter of matching names:

<label> Your email (required)
    [email* your-email] </label>

<label> First name
    [text your-first-name] </label>

<label> Last name
    [text your-last-name] </label>

<label> Phone
    [tel your-phone] </label>

[submit "Subscribe"]

Map your-email to Email Address, your-first-name to FNAME, your-last-name to LNAME, and your-phone to PHONE inside the Contact Form 7 Mailchimp plugin. Address is deliberately left out: it is a six-part compound field, and a single text input cannot fill it correctly. Collect addresses only if you genuinely segment by geography, and map the sub-fields individually.

The defaults are already there

Do not create FNAME, LNAME, ADDRESS, or PHONE in Mailchimp before mapping. They exist in every audience, and Chimpmatic maps to them immediately.

Hidden fields accept data via the API

Chimpmatic writes through Mailchimp’s API, not through the signup form, so it populates the hidden Address and Phone fields without you making them visible.

Custom fields must exist in Mailchimp first

Collecting anything beyond the defaults (company, birthday, website) requires creating that audience field in Mailchimp first: Audience > All Contacts > Settings > Audience Fields and *|MERGE|* Tags > Create a New Field, then map it in Chimpmatic’s settings in WordPress.

Only email is required for a successful submission

A CF7 form with just an email field subscribes contacts perfectly well. Everything else is optional enrichment.

Watch the 30-field limit on complex forms

Each custom field counts toward the audience limit. For categorical data, use Mailchimp tags, which Chimpmatic also supports, instead of burning field slots.

Frequently Asked Questions

How many default fields does Mailchimp create?

Five: Email Address, First Name, Last Name, Address, and Phone Number. They are created automatically with every new audience, on every plan, whether the audience is made in the web app or via the API.

Can I rename the default merge tags?

Yes, in the Audience Fields and Merge Tags settings. But Mailchimp reserves certain names, and integrations that expect the standard tags (FNAME, LNAME, ADDRESS, PHONE) can break after a rename, so never assume every audience uses the standard set.

Can I delete the default fields?

You can delete First Name, Last Name, Address, and Phone. You cannot delete Email Address. Deleting a field permanently removes that field’s data for every contact in the audience.

Do all Mailchimp plans get the same default fields?

Yes. Free, Essentials, Standard, and Premium all get the same five. The plans differ only in the total field cap: 30 on standard plans, 80 on Premium.

Why does the Address field require specific sub-fields?

It is a compound, structured field. Via the API it takes addr1, city, state, and zip as separate values (plus optional addr2 and country), which is what makes geographic segmentation by state, city, or zip possible.

What is the difference between the Phone field and the SMS Phone Number field?

The default *|PHONE|* field is general-purpose contact data. The SMS Phone Number field is a separate, dedicated field tied to Mailchimp’s SMS Marketing program, only available once SMS is set up, and it is the one SMS campaigns require.

Can I have more than one audience?

Yes, but Mailchimp recommends one primary audience organized with tags, segments, and groups. Audiences are fully independent: contacts in two audiences are billed twice, and each audience gets its own default fields and merge tags.