Export your existing list
Export a CSV from your current provider. Preserve unsubscribe information and confirm that you have permission to email the people on the list. Never use purchased or scraped addresses.
Prepare the file
In Studio, open Audience for your publication and choose Import contacts. Download the sample CSV to see the supported email, status, and source columns. The importer accepts up to 5,000 rows and a 1 MiB file. Use pending when consent is not yet confirmed; do not import payment status.
Review before importing
Upload the file to see valid rows, duplicates, existing records, and unsubscribe changes. The preview does not send email or add contacts. Confirm the permission statement only when you can substantiate it.
Keep existing reader choices
Existing billing records are preserved. A previous unsubscribe is never reactivated by an import. An incoming unsubscribe can suppress an existing contact. An imported confirmed contact may receive future issues and enabled lifecycle messages, so review your automation before committing.
Check your audience
Use status and source filters after importing. Export the filtered list when you need a copy. If a preview expires, upload the file again and review the refreshed totals.