An improved system and method that allows a customer waiting, for example, in a call center queue to leave contact information, a preferred callback time frame and drop out of the queue. The system and method computes a priority access code and a time frame when its use is valid that coincides with the preferred callback time frame of the call center or customer service department, etc. In response to the request for a priority access code to use when the customer calls back, the system and method sends the customer a callback message including the priority access code and time frame when its use is valid. During the time frame the priority access code is valid, the customer contacts the call center for example by calling back or by initiating a web chat, etc., re-enters the queue and uses the priority access code. This allows the customer to enter a general queue at their convenience and at a higher priority or go straight to the head of the general queue. Alternatively, the customer may enter a callback queue, which already has a higher priority than the general queue.