Area code 531 is an overlay for area code 402, covering eastern Nebraska, including the cities of Omaha and Lincoln. It was introduced in 2011 due to growing demand for new phone numbers in this rapidly expanding region. Ten-digit dialing is mandatory for all calls within the 402/531 area. While 402 retains legacy status, 531 is frequently used for newer mobile lines and business numbers. This area code supports the state’s economic centers and continues to grow alongside tech startups, universities, and healthcare systems. 531 is increasingly common in eastern Nebraska’s modern communication landscape.