SIP Trunks for
Professional Services

Unlike other types of organizations, professional services firms sell knowledge and expertise rather than physical products. For that reason, developing trust is an essential skill for attracting and retaining clients. Your customers expect nothing but effective and frequent communication, especially over the phone. At the same time, you want to be able to offer your services at competitive prices and keep costs down to maximize profits.

That's why professional services firms in every field including accounting, legal, business finance, engineering, architecture and more are making the move to cloud communications. SIP trunking provides an easy transition from legacy phone lines to internet-based, modern, unified communications systems without a big up-front investment. With SIP, your firm can cut costs and increase flexibility while providing even better service to every customer.

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What is SIP Trunking

Session Initiation Protocol (SIP) trunking is an alternative to traditional physical telephone lines. It allows for communications capabilities using the existing high-speed internet connection without the need for PRI lines. With a SIP trunk connected to a compatible PBX system, office workers can make calls to any phone number. Each SIP trunk supports a number of SIP channels. The number of channels determines how many calls can be active at one time.

The terms SIP and VoIP (Voice Over Internet Protocol) are often used interchangeably, but they are not the same thing. SIP is the technology that makes a VoIP call possible, but SIP channels can handle more than just voice traffic. They also support high-definition video, making them ideal for firms that use video conference calling.

The Benefits of SIP Trunking for Professional Services Firms

There are a number of compelling reasons that SIP trunking is so appealing to those who provide a wide variety of professional services.


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Lower Costs

The use of a SIP trunking service lowers costs for firms in a couple of ways. Firms can eliminate expensive physical telephone lines (PRIs) that are often linked to long-term contracts and include unpredictable long-distance charges. Instead, SIP.US offers long-distance calls to the lower 48 states and parts of Canada at no additional per-minute charge. Firms can predict and control communications costs. And unlike PRI lines that are sold in groups of 26, your firm can order the exact number of SIP channels that you need. If you need 30 concurrent lines, you pay for 30, not 52. If you need 3, that's all you have to pay for.

Many professional services firms realize telecommunications savings of as much as 50% when they switch to SIP trunking.

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More Flexibility

The needs of a firm can change quickly. The traditional approach to communications requires making guesses about your needs long into the future. This is not the case with SIP trunking. Firms can easily add or remove SIP channels on the fly when needs change, even seasonally. SIP.US makes it easy for administrators to make changes or cancel on-demand.


Streamlined Network Management

Most professional services firms don't have extra IT resources looking for something to do, so it doesn't make sense to complicate matters by having two networks to manage, which is the case when telephone and internet networks are entirely separate. With SIP, you have just one network for both, and your IT resources can focus on other priorities.


Direct Inward Dialing (DID)

SIP trunking gives you the option of assigning a 10-digit phone number to each employee, department, or room. You can create a call flow that works for your team and clients. Instead of hard-wiring these numbers to one location, users can "log-in" with their assigned phone number from any phone, simplifying office moves, or typical daily workflow. If you already have direct numbers or other numbers that you'd like to keep, no problem. They can most likely be ported to your new SIP trunking service.


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Disaster Recovery

In the event of a natural or human-made disaster, it may be more important than ever for clients to be able to reach your team. Even if you can't get into the office, or power is lost at one or more locations, your SIP service can redirect your calls to other offices, mobile phones, or even home land-lines. SIP.US protects your communications infrastructure by having redundant data centers, so a failure at one data center won't impact your ability to service clients.

Why SIP.US Professional Services Firms Choose SIP.US

While there are many built-in benefits of SIP trunking for professional services firms, keep in mind that not all SIP services are the same. Before you decide what's best for your team and clients, you'll need to compare the features, costs, and support services offered by each SIP service provider. SIP.US is an excellent choice for professional service firms and agencies because we make it easy.

  • Simple Pricing

    Profitable firms are careful about how they spend every dollar, so we are transparent about the cost for every element of our services. Our pricing is straightforward; we charge a low monthly fee for each SIP channel and no setup fees. We offer low rates for local and toll-free direct dial numbers and publish our rates for international calls. All of the details are available right here.

  • Self-Service When You Want It

    Our control panel is user-friendly even for people without telecommunications backgrounds. Your team can easily make moves adds and changes, review call detail records, and monitor the health of your telecommunications system. If you run into something out of the ordinary, our expert team will jump right in to help.

  • Compatible with Many PBX Solutions

    Our SIP trunks can be used with almost any internet-enabled (IP) phone system, whether it is at your location or hosted by a third party online. We are also compatible with the many free, open-source PBX systems available. If your legacy phone system isn't internet ready (if it's less than ten years old, it probably is), it may be possible to connect it with an inexpensive adapter.

  • On-Demand Growth

    With SIP.US you get and pay for exactly the number of SIP channels you need at the given time. If you want to add channels, cancel a few, or discontinue service entirely, you can do it on-demand in the control panel. There are no contracts, and you are not required to maintain a minimum number of channels.

  • Free Trial

    We know that communications are vital to your firm, so we don't ask you to take our word for it. We offer 60 minutes of free calling for you to try out SIP.US with your equipment, in your office. We don't even require a credit card to get started. It is easy to set up in less than two minutes, so you can give it a try and move forward with confidence.

  • First-Rate Network Infrastructure

    SIP.US utilizes only Tier-1 upstream providers to route our SIP traffic. We do this to ensure that you get the highest quality voice experience and a redundant network for outstanding reliability and performance.


Probably. If the system is fewer than ten years old, it is probably internet ready. If your IT team wants to keep control over the physical phone system, but still leverage new unified communications features, there are low-cost (sometimes free), open-source alternatives, such as Asterisk and FreePBX available. SIP.US is compatible with those as well.

If you have an old legacy PBX or key system that is not IP enabled, you may still be able to use SIP trunking by attaching an inexpensive device called an ATA (analog telephony adapter).

Find out how your organization can benefit from SIP trunking by getting your free trial today.

Get Your Free SIP TRUNK in 60 Seconds.

Customer Feedback

Here is what our customers have to say about working with SIP.US.

Simple Interface.

We were able to get our systems up and running with SIP.US in a matter of minutes using the simple online interface.

Matt Harrison

Elevate Audio Visual

Low cost and good!

It’s easy to be low cost, but it’s a lot harder to be low cost AND good! In my opinion, SIP.US should be on anyone’s short list of primary providers.

Michael Dodds


All the tools I need.

The SIP.US Control Panel gives me all the tools I need to add, change and delete phone numbers. I can even order all the DIDs I need and set them up instantly. I love having access to these self-service tools, but I know the support team is also there if I need additional help.

Colin Cook

Thimble River

Up and running in minutes.

We are able to get our Switchvox systems up and running with SIP.US in a matter of minutes using the simple online interface.

Mike Crockett

BITS Technology

Quality support, low price.

I wasn’t sure how to configure my Asterisk system to work with SIP.US. The SIP team was able to remotely access my system and set it up for me. I didn’t expect that level of support for such a low price.

Greg Galvin

The Galvin Law Group

Fast and easy set-up.

I don’t have any experience with SIP trunking, but connecting my Asterisk PBX to SIP.US was fast and easy.

Eddy Pareja

Sangfroid Web Design

Excellent support.

The reason we moved most of our VOIP to you is because of your excellent support. We moved from another provider but your support makes the extra money well worth it.

Brian Marshman

CEO BMI SmartCloud