About Us

Get To Know ESI


Estech Systems, Inc. (ESI) delivers high-performance cloud and on-premises phone systems that are easy to use and uniquely integrated. ESI provides end-to-end communication solutions that give businesses the power to choose the features that they need to meet their goals. ESI is a privately-held corporation headquartered in Plano, Texas.

Founded in 1987, the company has sold over 400,000 phone systems and deployed more than three million phones nationwide. ESI was the first company to build a truly combined telephone and voice mail system, as well as the first to build a purely IP-based business communications system, and has numerous patents granted or pending on its products' unique designs and capabilities. ESI is highly regarded for supporting uniquely integrated, real-world applications with practical and effective features.


Our Core Values

Our purpose is to contribute to our customers' success by making it easy to communicate!

  • Deliver products and services that are intuitive and easy to use.

  • Practice "Success with Significance."

  • Enjoy a fit, friendly and fun work and life style.

  • Encourage growth through employee and family education.

  • Provide an exceptional customer experience.

Our Patents


ESI has a number of U.S. Patents, either granted or pending, on our products’ unique designs and capabilities. Our innovative products use significantly less hardware, resulting in increased reliability. Due to our diversity of products and additional features, we provide significant benefits and greater long-term customer satisfaction. Our patents that have been granted include:

  • 6,067,349 and 7,221,741 - Dialing using Caller ID.
  • 6,252,944 - Telephone call/voice processing system
  • 6,842,505 - Communications system enhanced with human presence-seeking capabilities
  • 6,925,167 - Service observing in a voice over IP telephone system
  • 6,940,962 - Dial-on-hold
  • 7,068,684 - Quality of service in a voice over IP telephone system
  • 7,123,699 - Voice mail in a voice over IP telephone system
  • 7,564,834 - Shared knowledge in a telephone system