To reach QB Desktop support by phone, dial their toll-free number at. This number will connect you directly to QB Desktop support, where you can get help with any questions or issues related to the software. To contact QB Desktop Customer Support you can call their dedicated phone number at. These numbers are available to Enterprise assistance with any issues you may encounter while using QB Desktop Products and services. The QB Desktop Support Phone Number is. This support line is designed to help users with technical issues, account management, and general queries related to QB Desktop software.