Pros / A caller ID key will store caller information up to 25 days with this system. ESI also provides an emergency 9-1-1 alert.

Cons / You cannot reach customer service representatives via live chat. In addition, we could not find any FAQs or educational articles on the company website.

 Verdict / ESI is easily one of the best providers for small-business phone systems. This company offers many tools to help you market, secure and increase productivity in your office.

Editor's Note: This review has been removed from our side-by-side comparison because it no longer ranks as a top 10 product. The original review is below, but check out our current top small business phone systems here.

ESI is a powerful small-business phone system that can help you effectively communicate with your customers. This system is our Top Ten Reviews Silver Award winner because it offers customizable tools to help you market your specific business, productivity options such as instant messaging and unified messaging options as well as many security precautions. Whether you work in a call center or in retail, this solution provides numerous office phones that will best meet the needs of your company.


ESI’s phone system can integrate directly with your computer, making it much easier for you to enter, find or share information during phone calls. With this small-business phone system, unified messaging options are available. This allows you to receive any voicemails directly in your email inbox so you never miss any important messages again. You can also access the email inbox and your voicemails through your mobile device so no matter where you are, you are aware of who is trying to get ahold of you.

One standout feature available from ESI is its instant messaging capabilities. This allows you to easily communicate with other employees so if questions or concerns arise, help is always available and questions can be readily answered. This tool eliminates the need to constantly put customers on hold to find answers to questions. This feature is not available on many small-office phone solutions.


This office phone solution's feature set met our full expectations. It provides all of the basic calling features you need in a phone. It also offers several marketing tools, including the ability to customize the hold music or create messages for customers to listen to while on hold. You can also customize each voicemail message.

ESI can help you keep callers happy by providing an auto attendant to direct calls and minimize call transfers. It will also automatically transfer calls if one individual is busy or cannot take the call. This tool allows the customer to find a person who can help instead of being sent from one unanswered call to another. You can also change the route calls take based on the time of day or during holidays.

ESI provides advanced features such as live call recording so others can easily listen to your phone call. If an emergency occurs and you need immediate help, a 9-1-1 alert is available. Another safety and security measure is the Caller ID Key. This stores all of the caller ID information for the past 25 days within the system. You can use it to see exactly who is calling, especially if an individual’s excessive calling gets out of hand.

Another advantage to using this system is that it will work with wide variety of phone options. IP phones, softphones and DECT phones are just a few of the choices available from ESI. The phones have many similar features but different designs. The larger selection of phones allows you to choose a product that will work best for the type of work your company accomplishes.

Help & Support

All of the equipment from ESI comes with a five-year warranty. This is the longest warranty we saw for this type of product. Additionally, ESI offers a large selection of online support resources, including a handful of video tutorials, a company blog and testimonials. However, we couldn’t find any FAQs, white papers or educational articles on the website, which is disappointing.

If you want to reach a support representative, email and telephone options are available. Our interactions with representatives from this company were some of the best we reviewed. The knowledgeable, friendly representatives were willing to provide us all the information we desired. However, ESI does not offer live chat support, which is a drawback.


ESI provides an outstanding phone system for small businesses. This small phone solution provides the tools to easily market your company and increase your employees’ productivity while still maintaining high-quality communication with customers. This office phone system also provides an extensive feature set with all of the basic calling features you need in a phone. Additionally, we were impressed with this system’s warranty and the company's willingness to assist us. ESI can help improve your company’s communication and is easily one of the best phone systems on the market today.