Here is a quick guide on how to export from WHMCS to CSV:
Log in to your WHMCS account
Go to Reports menu and select Exports specifically by checking the Clients box
Use the Filter option and check the boxes for First Name, Last Name, Company Name, Email, Creation Date, Notes, Status and/or any other information you need to be exported to the CSV
4. Go in the top right corner and click on Tools
5. Select Export CSV , wait for the generation of this CSV file and download it.
6. Use CSV file to import customers right away in your Retently account using our CSV import guide here