We Empower Business Communications

From making a basic phone call, to video conferencing, to chat and SMS messaging, todays business communications take many forms.  Mastor is here to help. In St. Louis, the surrounding area, and nationwide, our clients range from the single entreprenuer, to multi-location retail, from pre-schools to colleges, from small doctor’s offices to larger medical facilities.  No matter your size we offer exceptional ongoing support unmatched in the industry.  We are THE TRUSTED solution for VoIP services in St. Louis.

Cloud PBX & UCaaS

Mastor is proud to be a platinum partner for one of the leading Cloud PBX and Unified Communications (UCaaS) providers in the country, NUSO.

SIP Trunking

As a NUSO platinum partner, we can offer significant savings on your monthly phone bill, even if you have an existing on-premise telephone system.

On-Premise Phone Systems

Mastor is proud to partner with Epygi, a leading manufacturer of feature rich, economical, and scalable on-premise VoIP systems.

Video Surveillance Systems

Mastor is proud to partner with Turing AI, a leader in the industry. We can  expertly design and install cutting-edge Video Surveillance Systems to protect your business.

Voice & Data Cabling

Mastor is here to help with your low voltage telephone and data cabling needs.  Whether you need to add a location for a new employee, are opening a new location, relocating your business, or expanding, we can help with your cabling and network infrastructure needs.

Our Customers

“Working with the teams at NUSO and Mastor Telecom Networks has been a great experience for our growing staff.  Between the sales team and technical support staff, they have met and exceeded our expectations throughout the entirety of our 5 year relationship.  They are easy to work with and always responsive when we have a ticket item to handle.” Read More

“Mastor has provided our law firm data services for nearly 20 years. Mastor is a very reliable, professional and trustworthy company with very knowledgeable, capable and friendly employees. They provide data services based upon our company’s needs. They take the time to listen and make recommendations and make sure that the customer fully understands.” Read More

“We have been working with Mastor for the past few years and it has truly been a positive experience. We are a financial institution with 9 offices spanning from Springfield, IL to metro St. Louis with approximately 175 employees. The technicians are extremely knowledgeable and will actually share the technical know-how with you if you are interested in performing some of the routine maintenance that comes along with managing a telecommunications system.” Read More

“Brian and his team are exceptional. One thing I really like is doing business with other local small business owners. The Yealink phones are great, boringly reliable which is exactly what we want! I’d leave 6 or 7 stars but google only allows 5!”Read More

Years in Business

Number of Customers

Lines in Service

Why Choose Mastor?

We pride ourselves on becoming an ally to our customers through our consultative sales approach. Our goal is to help you maximize your team’s productivity while minimizing costs.

No Major Upfront Costs

With Cloud PBX service we can wrap your upfront costs into a low monthly payment which makes budgeting a breeze

The Last Time You Will Need To Change your Telephone Service

With NUSO Cloud PBX service your software is always current. Moves, adds and changes are included, and your system grows with you.

Premium Customer Service

Our amazing support team is available 24/7 and is the best in the industry

Customized Plans

Service plan options allow you to customize needs by user. And as their needs change, the flexibility offered allows for rapid response by our team.

Replacements Included

Include your hardware in your monthly fee and receive replacements for the life of your service