The Truth About SIP Trunk Pricing and Implementation Costs

Disclosure: Our content is reader-supported, which means we earn commissions from links on Crazy Egg. Commissions do not affect our editorial evaluations or opinions.

If you’re looking into SIP trunk costs for your business, you’ve likely compared this internet-based system to traditional Primary Rate Interface (PRI) trunking via the older copper wire network. The majority of business owners today are cutting their telecommunications costs by as much as 40 percent, thanks to the more advanced features and overall efficiency of Voice over Internet Protocol (VoIP) solutions. Session Initiation Protocol (SIP) trunking is one aspect of this new technology.

On average, a business can expect to pay a leading VoIP provider $10 to $25 per SIP trunk each month—roughly $1 to $2 per user, though this can vary based on your business’s overall call volume. If you’re not sure how many trunk lines your team needs, a good method to follow is the “3:1 rule,” allocating one SIP trunk for three people who will be making calls at the same time. So, if you have 30 employees, you’d likely need about 10 SIP trunks. Again, depending on your call volume, you may need a higher or lower ratio of employees to trunks.

Before you dive into setting up your service, though, it’s important to understand that these estimated monthly prices aren’t the whole story. In order to get a better picture of what SIP truly costs, we’ll need to look at a few additional aspects of VoIP service.

SIP Trunk Pricing is Always Arbitrary

Phone system functionality used to be dictated by the physical nature of its infrastructure: hundreds of copper wires running across miles of ground.

If a business wanted to ensure that team members could make or receive calls as needed, a trunk—or group of phone lines—had to be reserved with the phone company. Each trunk was limited to handling only a certain number of concurrent calls, which businesses paid for regardless of whether or not they used them.

Today, SIP enables a phone connection whenever you need it over an internet network that is limited only by your bandwidth, not by the number of wires available.

Some VoIP providers offer trunks in groups of 10 to 20 “lines” as a simpler way to package their services. This is just an easy way to structure their pricing, but it’s not an actual physical limit. There is no additional hardware or installation required in order for your VoIP provider to add or remove trunks from your network.

To get a real sense of your SIP pricing, you’ll need an understanding of how your specific VoIP provider packages their trunk lines and exactly which features or services are included in your plan. Some providers may use different terminology or may define the same terms differently, so it’s especially important to figure out the exact pricing structure and fees you’re signing up for.

SIP Trunk Pricing Structures

Each VoIP vendor approaches SIP pricing a bit differently, depending on which features, fees, and limits they associate with your service. Typically, you’ll find that most providers follow four basic pricing structures:

  1. Elastic SIP Trunk Pricing: Also called “unmetered” pricing, this plan offers unlimited minutes per user. While that sounds like an amazing deal, you should note that “unlimited” is defined as 3,000 to 3,600 minutes—so it’s not actually unlimited. Still, if your sales team or other associates expect a high monthly call volume, this plan might be your best bet. Just note that you may incur high overage costs should your team exceed the set usage range.
  2. Metered SIP Trunk Pricing: In contrast to the unlimited approach, this plan offers a pay-as-you-go model. Also referred to as “usage-based” billing, this model only charges for the minutes you actually use, which is ideal for a smaller team or startup.
  3. Block SIP Trunk Pricing: Some providers allow for blocks of minutes to be purchased in advance each month, which works well if you have a pretty good idea of how much call time your team typically requires. Should you go over your block limit, you may pay a higher rate for additional minutes used.
  4. Per SIP Trunk Pricing: This method is the most similar to traditional PRI pricing, requiring a flat monthly payment for each virtual “bundle” of lines ordered. Pricing can vary greatly, as VoIP providers group anywhere from 10 to 100 lines in each trunk and charge from $10 to $60 per trunk. This model can work well for any size team, as long as you inquire about a vendor’s specific trunking structure before committing.
  5. Per Channel SIP Trunk Pricing: Rather than pay per bundle of lines, you can pay per line or “channel.” This is an ideal solution for any business that requires a lot of flexibility, as it allows you to scale up or down as needed.

When considering which cost model works best for your organization, be sure to ask about the cost of additional services and features. For instance, some VoIP providers offer call data encryption at an additional fee while others include it in their pricing structure. Either way, in today’s high-tech culture, you absolutely need this extra layer of security to guard against common cyberattacks on business PBX networks.

Nextiva pricing for metered and unmetered SIP trunking plans.

Also, keep in mind that certain VoIP providers charge differently based on the direction of your call. In other words, you might be charged less per minute for an inbound call than for an outbound call. Not all providers do this, though, so be sure to find out when you’re comparing services.

Beyond the Headline Cost of SIP Trunk Pricing

When you’re planning out your SIP trunking costs, price per user is far from the only aspect to consider. While certain VoIP providers don’t charge a setup fee, there are several additional charges you may find on your bill. Some of these appear only once during service initiation and others are charged every month. These fees can include:

  • Setup Costs: If your provider does charge for initial setup, the cost usually ranges from $50 to $300 and covers your consultation, implementation, onboarding, and Quality of Service (QoS) testing to ensure a working system.
  • Portability Fee: Your provider may carry over your previous business phone numbers to the SIP system.
  • Federal Universal Service Fund (FUSF) Fee: Regulated by the Federal Communications Commission, this fee is charged monthly and usually ranges from 15 to 33 percent of your total service fee.
  • Regulatory Recovery Fee (RRF): This monthly fee is typically charged per line, per month to help offset your provider’s costs of service, such as state and local sales taxes.
  • Enhanced 911 (E911) Fee: A legal requirement since 2005, this fee ensures that your geographic location is available to emergency services when dialed from any of your virtual lines.
  • PBX Configuration Fee: If you’re using an on-premises Private Branch Exchange (PBX) system, the VoIP provider may charge for any time and effort required to sync with your equipment or network.
  • Bursting Fee: This covers any extra channels used during periods of higher-than-anticipated call volume.
  • Load Balancing Fee: Your provider may choose to distribute heavy call traffic across multiple servers.
  • 411 Directory Fee: Your business is legally required to notify directory services of any contact updates, and your provider may charge a fee for managing this task.
  • Call Forwarding Fee: Charged when your provider forwards calls to an alternative number, extension, device, or voicemail.
  • DNIS/ANI Fee: Charged for Dialed Number Identification Service (DNIS) or Automatic Number Identification (ANI) service that captures caller information.
  • Direct Inward Dial Fee: Covers any team member who is assigned their own virtual Direct Inward Dial (DID) phone number on your PBX network.
  • Toll-Free Lines: Your business will typically be charged an additional monthly flat rate for any toll-free lines required.

SIP Trunk Maintenance and Security Costs

In addition to the fees charged by your VoIP provider, you may also need to consider any costs associated with maintaining an on-premises PBX system.

True, an onsite solution affords you greater control over system accessibility and functionality. You can set your own security protocols and select from any cloud- or software-based virtual phone features without feeling limited by what a specific VoIP provider offers.

Plus, following the initial installation of your system, you can easily scale up your network as your business grows, enjoying a very low monthly cost per user—and free of all the potential fees associated with a VoIP vendor-hosted service.

However, should you opt for an on-premises network, you’ll also need adequate space to house your servers, computer interfaces, and other hardware, which represent a heavy upfront investment.

Additionally, you’ll likely want to staff at least one full-time IT position to troubleshoot any security, software, or hardware issues when necessary and keep your system running smoothly.

This represents an additional ongoing SIP system-related cost that you should take into consideration as you plan your budget, and it’s a cost you can significantly lower by paying a VoIP vendor to host a cloud-based PBX for you.

No matter which route you choose for your business, remember to dig a little deeper when it comes to comparing VoIP provider pricing plans, keeping in mind aspects like your company’s current size and potential growth, overall phone usage, as well as hidden service fees not included in the base monthly price.

Make your website better. Instantly.

Over 300,000 websites use Crazy Egg to improve what's working, fix what isn't and test new ideas.

Free 30-day Trial