Start by downloading sample CSV - this way you can check what fields are possible to import, and how to prepare CSV file.
One you have your csv file ready click on Upload your CSV file button, select your CSV file and click on Import - HostBill will begin import process. Customer e-mail is used as unique field, If duplicated emails are detected, HostBill will skip them.
To reduce database load, processing time when importing large customer datasets, split your CSV into multiple files, ie. by limiting to 300 rows each.