If you are UPDATING existing memberships, you will need to include a column containing the unique CiviCRM-assigned membership ID to match to the existing membership records.
If you are UPDATING existing memberships, you will need to include a column containing the unique CiviCRM-assigned membership ID to match to the existing membership records.
If you are UPDATING existing memberships, you will need to include a column containing the unique CiviCRM-assigned membership ID to match to the existing membership records.