Format List Fields

This feature requires Manager user level or higher.

Before you import subscribers to your MailChimp list, review the format of each field in your import file. Certain list field types, like addresses and phone numbers, require a specific format.

When you import files, be sure the character encoding is UTF-8, and that field labels in your file match the field labels in MailChimp. If you've already imported a list or created fields, navigate to the Lists fields and *|MERGE|* tags page to review or edit the field labels.

In this article, you'll learn how each field type should be formatted to yield consistent results in MailChimp.

Email Address

When you import subscribers from a file, be sure the file includes a column for email address, and include only one email for each subscriber.

Also be sure your entries don't contain special characters before the @ symbol, or spaces anywhere in the address.


When you add an address field to your signup form in the Form Builder, it displays several fields where subscribers enter data. When you include an address in your import file, however, the entire address should appear in a single cell and include the country. 

Format each address cell with all parts of the address separated by two spaces, as shown in the following example.

How the address looks on your form:

1701 Bristol Ave. 
Barrington, Rhode Island 02806

How the address is formatted in your import file:

1701 Bristol Ave.##Barrington##Rhode Island##02806##USA

"##" represents two spaces in the example above, but don't include pound signs in the actual file. 

If a subscriber doesn't have a second street address line, just skip that line. The system will sort the fields correctly.

address format screenshot


To send an automatic birthday or annually recurring message to your subscribers, use a birthday field instead of a regular date field. To import a birthday, be sure to use the format Month/Day:


birthday format list


Two date field formats are available to you. 

YYYY-MM-DD (ISO Standard)

In the examples above, MM is month, DD is day, and YYYY is a four-digit year. MailChimp will attempt to convert the date field to match the account's default date format. For best results, we recommend that you use the ISO standard format, YYYY-MM-DD.


Image fields in your import file should contain the URL for a hosted image, which can be used to insert custom, dynamic images in campaigns.

In an import file, include the full image source address with the "http://" at the beginning.


U.S. phone numbers should be in the following format with no spaces, parentheses or dots.


International numbers typically don't fit this format. If you have international subscribers, choose the international phone number option when you create a phone number field on the signup form. 


Text fields are limited to a maximum of 255 bytes of information. In many alphabets, this is equal to 255 characters. Some alphabets or symbolic characters, like emoji, use more than one byte of information per character, so it isn't always a one-to-one ratio. Anything greater than 255 bytes will be clipped.

Text fields also accept numbers. Unlike number fields, text fields don’t include comma separators in the number. For example, use a text field if you want your number to appear in your list as 1000 instead of 1,000.


Website fields must include the full URL of the subscriber's website, including http://.

website example

Zip Code

Zip code fields can only contain five digits and don't support international postal codes. 


To store international postal codes, use a text field. If you have subscribers in many locations including the U.S., use both a zip code field and a text field on your signup form.


Use a number field to import numbers or currency values to your list.

We'll add comma separators to large numbers like 1,000 or 1,000,000.


Create groups in your list before you import your subscribers, so they can be assigned to the groups during import. Be sure to format the group column properly, or you may encounter errors with your import.

The column label should be the group title. For each subscriber, include each group name the subscriber should be added to. For multiple group names, separate them with a comma. 

For example, if your subscribers can choose from Student Events, News, and Donations and a particular subscriber chooses all three, a row might look like this: Lilah Morrison         Student Events, News, Donations

Format list fields for groups

If you've already imported your list and want to add subscribers to groups, you can do that from the Lists section of your account.

Was this article helpful?
What can we do to improve articles like this?

Technical Support