Magento allows importing csv file for importing customers. It ‘must, however, comply with a precise import format.
To create the correct CSV file download this file that contains the pattern of accepted Magento.
Compile the file following the format as the first line.
Once the file is ready, proceed as follows:
1. Login into Magento backend (/ admin)
2. Select System, Import / Export, Dataflow profiles
3. Select the profile “Import Customers” by clicking on “edit”
4. Select “loads a file” to upload the .csv file to be imported
5. Select Run profile, select the imported file and Run profile in a popup
At this point part in the import process and will open another window to display the import-progress
Here you can see the processing result.