303 Area Code Colorado - Denver Boulder business phone and answering service
June 27, 2025

Get an Area Code 303 Phone Number and Answering Service for Your Business

Establish your local presence in Colorado's premier business region with a 303 area code phone number. Area Code 303 serves Denver, Boulder, Aurora, and surrounding communities, connecting your business to over 3.5 million potential customers in one of America's fastest-growing metropolitan areas.

Share this post
Explore AI Summary

Geographic Regions and Area Codes in Area Code 303

Area Code 303 covers a significant portion of central Colorado, including major cities such as Denver, Boulder, and Aurora. This area code also encompasses surrounding suburbs like Lakewood, Littleton, Longmont, Broomfield, and Castle Rock. The region is divided into 10 counties: Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson, and Weld. To accommodate the growing demand for telephone numbers, Area Code 303 is overlaid by area codes 720 and 983.

The 983 overlay was activated on June 17, 2022, following Colorado Public Utilities Commission approval to address projected number exhaustion. This addition maintains the same geographic coverage while providing additional numbering resources for the region's continued growth.

Key cities and their area codes include:

  • Denver: 303, 720, 983
  • Boulder: 303, 720, 983
  • Aurora: 303, 720, 983
  • Lakewood: 303, 720, 983
  • Littleton: 303, 720, 983
  • Longmont: 303, 720, 983
  • Broomfield: 303, 720, 983
  • Castle Rock: 303, 720, 983

Population and Demographics

The population within the 303 area code is approximately 3.5 million people. Denver, the largest city in this area, has a population of over 700,000 residents. Aurora, another major city, has a population of 386,261 as of the 2020 Census. The region is diverse and continues to grow, making it a vibrant area for businesses to thrive.

The 303/720/983 overlay complex serves 26 cities and 10 counties, reflecting the concentrated population density that drove the need for multiple area code overlays to meet telecommunications demand.

Time Zone

The entire state of Colorado, including the 303 area code, falls within the Mountain Time Zone (MT). During daylight-savings time it shifts to Mountain Daylight Time (MDT). This time zone is seven hours behind Greenwich Mean Time (GMT-7) and six hours behind during daylight savings (GMT-6).

Number of Small Businesses

The number of small businesses varies by city and county within the 303 area code. Denver, being the economic hub, hosts numerous multinational corporations and a thriving startup scene. The region benefits from Colorado's business-friendly environment, with VoIP technology adoption reaching 31% of businesses globally, reflecting the technological advancement of local enterprises.

Example counts for selected cities:

  • Denver: 1,341 hair salons, 226 barber shops, 16 computer-repair shops, 13 home-security providers, 42 spas, 69 wellness centers, 1,341 fitness gyms
  • Aurora: 226 hair salons, 20 barber shops, 16 computer-repair shops, 13 home-security providers, 42 spas, 69 wellness centers, 226 fitness gyms
  • Thornton: 16 hair salons, 20 barber shops, 16 computer-repair shops, 13 home-security providers, 42 spas, 69 wellness centers, 16 fitness gyms

Unique Story: Economic Growth and Opportunities

Colorado has experienced remarkable economic growth over the last several years, and the 303 area code is at the heart of this expansion. Denver serves as the economic nucleus, thriving as a hub for finance, technology, healthcare, and outdoor recreation. The city is home to numerous multinational corporations and a burgeoning startup scene, making it an attractive location for entrepreneurs and established businesses alike.

The region's robust telecommunications infrastructure supports this growth, with businesses increasingly adopting advanced communication technologies. Modern business phone systems in the area benefit from VoIP market expansion, which is projected to grow from $48.27 billion in 2025 to $136.74 billion by 2033, reflecting the technological sophistication driving Colorado's economic development.

The region's economic vitality is further bolstered by its diverse population and high quality of life, which continue to draw new residents and businesses to the area.

Benefits of Using Goodcall in Area Code 303

Goodcall offers a range of benefits for businesses operating in the 303 area code. As an AI phone service, Goodcall provides an affordable and efficient alternative to traditional IVR technologies, call centers, and voicemail systems.

  • Always Available: Goodcall's AI technology ensures that your business phone is never busy and always available to answer calls.
  • Cost-Effective: Replacing traditional call centers or voicemail systems with Goodcall can significantly reduce operational costs.
  • Easy to Use: The service is designed to be user-friendly, making it easy for small businesses to implement and manage.
  • Enhanced Customer Service: Goodcall's interactive AI capabilities provide a more engaging and responsive experience for your customers.
  • Google Voice Alternative: Goodcall can be used as a superior alternative to Google Voice, offering more advanced features and better performance.

For businesses in the 303 area code, Goodcall is an invaluable tool that can help improve customer service, streamline operations, and reduce costs. Whether you're running a hair salon, barber shop, plumbing service, or fitness center, Goodcall's AI phone assistant can handle your calls efficiently, allowing you to focus on growing your business.

Last updated:
June 27, 2025

Why A Local AI Phone Number

A local AI phone number links your AI agent to real-world calls.
‍
πŸ“ž Your agent answers calls 24-7 / 365 and is never busy
πŸ“ˆ Understand your callers with detailed analysis
πŸŽ™ Capture the detail in every call, they're all recorded
🌐 Forward calls or connect to Google Voice
βœ‹πŸ» Places callers on hold when your line is busy
🚫 Say goodbye to spam calls

An AI Phone Service With Smart AI Agents


Use skills to teach your agent how to respond to common caller questions.
‍
πŸŽ“ Teach your agent anything with your own custom skills
βœ… Off the shelf skill templates ready to go in a few clicks
πŸš€ Combine skills to create deeper customer engagement
πŸ‘‹πŸΌ Optimize customer experience with custom greetings
πŸ’° Grow revenue by textingΒ your website (ie: bookings & shop)

AI Agent which is automatically answering the phone to serve your customers.

Geographic Regions and Area Codes in Area Code 303

Area Code 303 covers a significant portion of central Colorado, including major cities such as Denver, Boulder, and Aurora. This area code also encompasses surrounding suburbs like Lakewood, Littleton, Longmont, Broomfield, and Castle Rock. The region is divided into 10 counties: Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson, and Weld. To accommodate the growing demand for telephone numbers, Area Code 303 is overlaid by area codes 720 and 983.

The 983 overlay was activated on June 17, 2022, following Colorado Public Utilities Commission approval to address projected number exhaustion. This addition maintains the same geographic coverage while providing additional numbering resources for the region's continued growth.

Key cities and their area codes include:

  • Denver: 303, 720, 983
  • Boulder: 303, 720, 983
  • Aurora: 303, 720, 983
  • Lakewood: 303, 720, 983
  • Littleton: 303, 720, 983
  • Longmont: 303, 720, 983
  • Broomfield: 303, 720, 983
  • Castle Rock: 303, 720, 983