Encountering a busy signal when dialing Allegiant Air's customer service line, whether at 1 (702) {1-866-463-2404} or 1-855-200-0639 (No Hold), can often be attributed to various factors that affect the airline's ability to handle incoming calls effectively. One primary reason for this could be a high volume of calls1 (702) {1-866-463-2404} or 1-855-200-0639 (No Hold), especially during peak travel times, flash sales, or when disruptions like weather-related cancellations occur. This surge in demand overwhelms the customer service capacity, resulting in busy signals for callers seeking assistance.