Manually add clients during checkout, in the Client Area, or in the Admin Area. Each customer must have a client account in WHMCS. The Summary tab in the Client Profile contains an overview of the client's details, billing and service information, and management quick links. Issues in the Client Area or your online store can hurt customers' ability to purchase your products or access their purchased services. The user management system can grant access for a single client's services, billing, and support to multiple users with separate logins. Add users manually, associate them with existing clients, and change the client account owner. Users own and manage client accounts. After purchases or other events, the system sends a message to the client using an email template. You can also email clients manually. Admins can manage affiliates, assign orders to them, pay commissions, and view referral and payout history in the WHMCS Admin Area. Make sure the details for a user and an associated client match by updating them manually. These details do not automatically sync. The Profile tab in the Client Profile lists the client's contact details and account options. Client groups allow you to categorize your clients. You can use client groups to set domain pricing slabs, apply discounts, and more. Email verification ensures that a client's registered email address is valid after client creation or changes to the email address. WHMCS allows you to ban specific email domains from creating new client accounts and users. You may wish to ban free email providers to prevent spam orders. Custom fields collect additional information from or about your clients. You can set them as admin-only or make them visible to clients. After you enable and configure the Affiliate system, you can convert existing clients into affiliates in the Client Area or Admin Area. Change a client's currency by creating a new identical client with and transferring invoices, services, and transactions to them. Configure WHMCS to automatically delete data for inactive clients after they have terminated all services and a period of time has lapsed. Configure two-factor authentication (2FA) for Client Area logins. 2FA enhances security by adding a second step to the login process. Export an individual client's data as a downloadable JSON file. You can use this to fulfill clients' requests for their own data. Offer clients the choice to opt in or out of your marketing email list during checkout or in their account details in the Client Area. Require all new customers to read and agree to your Terms of Service before they can place an order for your products or services.