Area code 423 covers eastern Tennessee, including cities like Chattanooga, Johnson City, Kingsport, and Cleveland. Originally part of area code 615, 423 was created in 1995 and is now complemented by overlay 729 in the Chattanooga region. Chattanooga has grown into a major tech and logistics hub, known for its high-speed internet infrastructure, startup-friendly climate, and outdoor recreation. Kingsport and Johnson City are part of the Tri-Cities region, with strong healthcare, education, and manufacturing sectors. East Tennessee State University and several regional hospitals contribute to local employment and innovation. Nestled near the Smoky Mountains and the Appalachian Trail, the 423 area blends natural beauty with economic opportunity. A 423 number connects your business or identity to a region that values community, tradition, and steady growth. Whether you're in healthcare, hospitality, or B2B services, it helps build regional trust.