Study first
Review the ideas behind the questions
Check the Mailchimp import file before the audience is used in a campaign. Focus on the required email field, permission for subscribed imports, update behavior, labels, groups, and skipped-row results.
Start with a clean import file
A contact import is mostly spreadsheet work before it is platform work. The file needs the right contact identifier, clear columns, and a format the import tool can read.
- Email contacts need an email address field in the import file.
- Other columns are optional, but they may be needed for personalization or segmentation.
- CSV or tab-delimited TXT files are supported for file uploads.
In Practice
Name columns for easy matching
Label spreadsheet columns in plain language so the importer can be matched to the right audience fields.
Fix obvious address problems first
Trim extra spaces and fix incomplete addresses before importing so real contacts are not rejected as syntax errors.
Common mistakes
Uploading a spreadsheet that has names and company names but no email address column.
Add an email address column before import because it is the required identifier for email contacts.
Q&A
Can a contact import work without an email address column?
No. For email contacts, the email address field is required.
Should optional columns be deleted automatically?
No. Keep optional columns that support the campaign plan, such as segmentation or personalization fields.
Choose the import action carefully
Import settings can add new people, update existing profiles, attach labels, or place subscribed contacts into groups. The safest choice depends on the data and the sender's permission basis.
- Imported subscribed contacts do not go through the signup process.
- Existing contacts can be updated during import when the update option is selected.
- Tags can be assigned during an import and can also be included in a Tags column.
In Practice
Verify permission before subscribed import
If the import will mark contacts as subscribed, confirm they gave permission to receive marketing from the sender.
Use tags for internal import context
A tag such as Trade show 2026 can keep the import source available for later targeting without making it a subscriber choice.
Common mistakes
Assuming an uploaded subscribed list has completed the same flow as a signup form.
Treat subscribed import permission as a separate check because imported subscribed contacts do not go through signup.
Q&A
What should be checked before importing contacts as subscribed?
Check that the sender has permission to market to those contacts.
When should the update-existing option be used?
Use it when the goal is to update profile data for contacts already in the audience.
Check what the import changed
A finished import still needs review. The results can show skipped addresses, duplicate handling, updates, and errors that should be fixed before the list is used.
- Duplicate, bounced, and unsubscribed addresses already in the audience are not included as new imported contacts.
- Blank fields can overwrite and erase existing information when updating contacts.
- The Import History page shows import errors for 24 hours.
In Practice
Review skipped rows before sending
If the imported count is lower than expected, check import results before building a campaign from the audience.
Protect existing profile data
Before using the update option, remove blank columns that should not erase saved contact data.
Common mistakes
Treating a lower import count as a platform bug without checking duplicate, bounce, unsubscribe, or syntax results.
Review Import History and skipped-row reasons first.
Q&A
How long are import error details available in Import History?
The details remain available for 24 hours.
Can a blank update column erase existing profile data?
Yes. Blank fields can overwrite and erase existing contact data when updating through import.