Domain Registrars
From WHMCS Documentation
Domain Registrar integration allows for automated domain registration & management through a WHMCS system. Available management features consist of:
- Domain Registration
 - Domain Transfers
 - Renewal/Extensions
 - View/Change Nameservers
 - View/Update WHOIS Information
 - Lock/Unlock Domains
 - ID Protection
 - EPP Code Retrieval
 - Register/Manage Private Nameservers
 - DNS Record Management
 - Email Forwarding Management
 
Most features are available for all but some are only available on certain registrars. For registrar specific information see the relevant articles below.
Guides on configuring domains & registrars in WHMCS can be found in Domains Management and we have prepared a video tutorial demonstrating how to configure a registrar @ http://www.whmcs.com/tutorials.php?i=7