Summary TabThe Summary tab in the Client Profile contains an overview of the client's details, billing and service information, and management quick links.
Custom PDF InvoicesInvoice and quote PDF files use a customizable template file system in the templates directory of the active WHMCS system theme.
Quotes TabThe Quotes tab in the Client Profile lists the client's existing quotes and allows you to edit them or create a new quote.
InvoicesThe Invoices tab in General Settings allows you to configure how WHMCS generates and sends invoices and applies late fees.
Question Marks in PDF InvoicesHow to troubleshoot question marks replacing text in PDF invoices and quotes.
QuotesQuotes allow you to send estimates to customers. If the customer accepts your quote, you can easily convert the quote into an invoice.