Why does my CSV upload for audience creation show rows skipped?

Rows are skipped during a CSV upload when the data does not match the requirements of the column you chose. If you map a column to HWID, the system checks the format of each value and whether it belongs to a registered device.

Incorrect HWID format

Mobile HWIDs are UUID strings: 36 characters — 32 hexadecimal digits split into five groups by hyphens (8-4-4-4-12), for example C8489DD9-8004-4E0B-9455-9EB9623A07C4. The parser rejects continuous strings without hyphens and other non-standard formats.

Note that Web SDK devices use a different shape: the HWID is your application code followed by an underscore and a UUID (for example XXXXX-XXXXX_1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d). Copy such values exactly as they appear in the Control Panel instead of trimming the prefix.

Mismatched identifier type

This error occurs if you upload one type of ID but label it as another. For example, if you upload a list of User IDs but select HWID in the mapping dropdown, the system skips those rows. Check that the mapping selection matches the data in your file.

Missing subscribers

The system skips identifiers that do not belong to any registered subscriber in the application you are uploading to. An identifier must already exist in that application's device base to be added to an audience.

To fix these issues: check your file for hyphens in HWID strings, make sure you are uploading to the right application, and if you are using User IDs, restart the upload and select User ID in the mapping menu. Also confirm that the users in your list have already registered in your app or website.