If you've previously deleted a contact but now you need to re-add it to your account manually, then the only solution would be to do it using our CSV contacts importer.

Basically, you will need to create a simple CSV file, which should include at least the email address of the contact that you need to re-add.

NOTE: Of course, if needed, you can fill the CSV file with more details for the contact and import them as well.

Next, upload the CSV file here: https://app.retently.com/customers/import and map the data that you want to import along with the contact.

On the next step, in the "Additional options" section, under the "Customer has been deleted in Retently" menu, select the "Re-add customer after upload" option.

Finally, finish the CSV file import and your contact should appear on the Audience page.

You can learn more about the CSV imported here: https://help.retently.com/en/articles/431296-how-to-import-a-csv-list-with-customers.