Customizing the Logo Image in Client Area
Changing the company name in the client area with your own logo image is really easy!
Navigate to Configuration > Setup Wizard (Help > Setup Wizard prior to WHMCS 8.0).
Click Choose File and locate the .png or .jpg image file you wish to use as a logo.
If you haven't already, you might like to complete the rest of the Getting Started Wizard steps.
Keep clicking Next until you reach the end of the wizard.
Your logo is now displayed on invoices and emails.