Yes, Taguchi can recognise an existing subscriber when you import into a list. It uses the identifying details you map, such as Email, Phone or External ID, to decide which profile to update.

For example, if Alex is already in Taguchi and your file correctly identifies Alex's profile, you can use the import to update their first name or add them to the selected list. You do not need to create a new profile simply because you are adding them to another list.

What if my file contains the same person twice?

Repeated rows in your spreadsheet are a separate issue. Taguchi can report a row as Duplicate when it detects an identifier that has already appeared while processing the file.

Before uploading a file with repeated subscribers:

1. Find the repeated rows, such as two entries for Alex with different details.
2. Combine the information you want to keep into one row.
3. Remove the conflicting copies.

Large files are processed in smaller groups. Do not rely on the last repeated row replacing earlier values.

If your row includes an External ID that Taguchi cannot find, Taguchi will not use the email or phone instead to find the subscriber. Review import logic before combining identifiers.

An import with only duplicate issues can finish as Import complete, with duplicates still listed in the error report. Resolve any conflicting details for the same subscriber in your spreadsheet before importing again.

List-level uniqueness settings are a separate control. See unique subscription enforcement.