Use the Contacts import to mark people as Do Not Contact. The import includes a Do Not Contact field, so you do not need to create a separate interaction for this workflow.
Prepare your file
Create a CSV with the person's name, a matching identifier such as their email address or phone number, and a Do Not Contact column. For each person you want to stop contacting, enter true in that column.
Use identifiers that match the intended contacts. The import can match existing people or create new contacts when there is no match. Review the rows carefully before you approve the import.
Import the list
Open Import & Export and choose Contacts.
Upload your CSV and choose the header row.
Map the name and identifier columns to their matching fields.
Map your Do Not Contact column to Do Not Contact.
Review the mapped values and import summary. Confirm the correct people have a true Do Not Contact value.
Approve the import and wait for processing to finish.
Verify the result
Open an affected contact's profile. Interaction History shows Communication disabled due to Do Not Contact. This status blocks calls, texts, and emails to that person.
The profile also provides a Restore control. Use it only when the contact should be available for outreach again. Clearing Do Not Contact does not override separate email or SMS opt-outs.
Do Not Contact is different from deleting
Marking someone Do Not Contact preserves their contact record and history. To permanently remove records instead, see How do I bulk-delete contacts?