When you have any queries, you just access the Comcast customer service phone number. There is also a toll free number available for you. Here are the lists of toll free numbers for contacting the customer support team that includes: 1-800-COMCAST (1-800-266-2278) – For billing, existing customers and technical support. For any queries, you can contact the above toll free number. Your call may be recorded or monitored for training or quality purposes. If the last 4 digits of your account mobile number are XXXX, then press 1 for confirmation.