Area code 303 serves the Denver metropolitan area in Colorado and is one of the state’s original area codes, established in 1947. Today, it covers Denver, Boulder, Aurora, Lakewood, and surrounding suburbs, and is overlaid by 720 and 983. The 303 area represents Colorado’s front-range urban corridor, known for its booming tech industry, outdoor recreation, and highly educated workforce. Denver is a fast-growing hub for startups, energy companies, aerospace firms, and healthcare institutions. Boulder, just northwest of the city, is home to the University of Colorado, national research labs, and a thriving natural products industry. The entire metro area benefits from a strong quality of life, attracting remote workers, investors, and young professionals. The 303 number remains a prestigious and recognizable code, especially for long-established businesses and organizations. Whether you're in SaaS, green energy, legal services, or craft brewing, a 303 number positions your brand in the heart of Colorado’s economic and cultural center.