Email Marketing
Mailchimp Audience CSV import requirements
Import contacts into a Mailchimp audience list with email validation. Below are the 10 columns the import expects, including 1 required field, the formats each one accepts, and the errors that most often cause a failed import.
Validate my Mailchimp Audience CSV freeMailchimp Audience CSV columns
Header names are matched automatically — the “also accepted” names are mapped to the correct Mailchimp Audience field.
| Column | Required | Type & rules | Also accepted headers |
|---|---|---|---|
| Email Address | Yes | Email address | email, Email, email_address, E-Mail, e-mail |
| First Name | No | Text | FirstName, first_name, First, firstname, FNAME |
| Last Name | No | Text | LastName, last_name, Last, lastname, LNAME |
| Tags | No | Text | tags, Tag, Labels |
| Phone | No | Phone number | phone, Phone Number, phone_number, PHONE |
| Birthday | No | Date, format MM/DD | birthday, DOB, Date of Birth, BIRTHDAY |
| Address | No | Text | address, Street Address, ADDRESS |
| City | No | Text | city, CITY |
| State | No | Text | state, STATE, Province |
| Country | No | Text | country, COUNTRY |
Common Mailchimp Audience import errors
- Column headers that don’t match Mailchimp Audience field names (for example "Email" instead of "Email Address").
- Missing or empty required columns: Email Address.
- Invalid or mixed-case email addresses, stray spaces, and duplicate emails across rows.
- Phone numbers in inconsistent formats (dots, brackets, missing country codes).
- Dates in the wrong format, for example DD/MM/YYYY where the importer expects another order.
- Hidden problems: wrong file encoding, a byte-order mark, extra blank rows, and leading or trailing whitespace.
How to check your file before importing
- Open the free validator and upload your CSV, TSV or Excel file — nothing leaves your browser.
- Choose Mailchimp Audience and confirm the suggested column mapping.
- Review the four-layer report: structure, formats, content and cross-field rules.
- Apply one-click repairs, then download the clean file and import it.