How to import subscribers from Mailchimp on ConvertKit

intermediate 8 min read Updated 2026-03-18

Quick Answer

To import subscribers from Mailchimp to ConvertKit, first export your subscriber data as a CSV file from Mailchimp, then use ConvertKit's subscriber import feature to upload and map the data fields. The process typically takes 10-30 minutes depending on your list size.

Try ConvertKit Full ConvertKit Review

Prerequisites

Active ConvertKit account
Access to your Mailchimp account
CSV export permissions in Mailchimp
Understanding of subscriber data structure

Step-by-Step Instructions

Export subscribers from Mailchimp

Log into your Mailchimp account and navigate to Audience > All contacts. Click the Export Audience button and select Export as CSV. Choose to include all subscriber data including email addresses, names, tags, and custom fields. Download the CSV file to your computer.

Make sure to export all relevant data including subscriber status and signup dates to maintain your list quality.

Access ConvertKit subscriber import

Log into your ConvertKit account and click on Subscribers in the main navigation menu. Then click the Import subscribers button located in the top right corner of the subscribers page.

Upload your CSV file

On the import page, click Choose File and select the CSV file you exported from Mailchimp. ConvertKit will automatically detect the file format and display a preview of your data. Review the preview to ensure all columns are properly recognized.

If your file is large (over 10,000 subscribers), consider splitting it into smaller batches for better import reliability.

Map data fields

ConvertKit will attempt to automatically map your CSV columns to subscriber fields. Verify that Email is mapped correctly, then map additional fields like First Name, Last Name, and any custom fields. Use the dropdown menus next to each column header to select the appropriate ConvertKit field or create new custom fields as needed.

Create custom fields for any Mailchimp data you want to preserve, such as signup source or subscriber preferences.

Configure import settings

Choose whether to Add new subscribers only or Update existing subscribers. Select the appropriate subscriber state: Active for confirmed subscribers or Unconfirmed if you need them to confirm again. You can also assign tags or add subscribers to a specific form during import.

Consider tagging imported subscribers with something like 'Mailchimp Import' to easily identify and segment them later.

Review and confirm import

Review all your import settings including field mapping, subscriber status, and any tags or forms. Click Import Subscribers to begin the process. ConvertKit will show you a confirmation screen with the number of subscribers being imported.

Monitor import progress

ConvertKit will process your import in the background and send you an email notification when complete. You can check the progress by going to Subscribers > Import History. Large imports may take several minutes to complete.

Don't start multiple imports simultaneously as this can cause processing delays.

Verify imported data

Once the import is complete, review your subscriber list to ensure all data was imported correctly. Check that subscriber counts match your expectations, custom fields populated properly, and any tags were applied correctly. Test a few subscriber profiles to verify field mapping worked as intended.

Send a welcome email to your newly imported subscribers to re-engage them and confirm they're receiving your emails properly.

Common Issues & Troubleshooting

CSV file upload fails or shows formatting errors

Ensure your CSV file uses UTF-8 encoding and has proper column headers. Remove any special characters or empty rows, and make sure email addresses are in a valid format.

Import gets stuck or times out

Large files may need to be split into smaller batches of 5,000-10,000 subscribers. Try importing during off-peak hours and ensure your internet connection is stable.

Duplicate subscribers are created

ConvertKit identifies duplicates by email address. If you have subscribers with different email formats (like extra spaces), clean your data first or use the Update existing subscribers option.

Custom fields don't map correctly

Create the custom fields in ConvertKit first before importing, or create them during the import process. Ensure field names match exactly and data types are compatible (text, number, date).

Prices mentioned in this guide are pulled from current plan data and may change. Always verify on the official ConvertKit website before purchasing.

Visit ConvertKit View ConvertKit Pricing