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Take your PBX to the cloud with Nextiva's SIP trunking

Seamlessly transition your legacy PBX system into a powerful cloud system. No new equipment or service disruptions.

Talk with an expert
Roman Voytsekhovskiy, Support Center Manager at Orthodontic Experts Ltd
“With Nextiva, the supervisor dashboard allows me to monitor call flow in real-time. It allows me to ensure I always have sufficient agent coverage, so that calls are never missed. I can easily make changes to my call flow without having to wait for hours on hold.” Roman Voytsekhovskiy, Support Center Manager at Orthodontic Experts Ltd.

What is SIP Trunking?

SIP trunking uses VoIP to move your Private Branch Exchange (PBX) system's call traffic over an internet connection. This way, your PBX connects with a Public Switched Telephone Network (PSTN) without traditional phone lines. No more Primary Rate Interface (PRI) or analog lines!

As for a SIP trunk...

A SIP trunk is a phone line that uses the SIP protocol. And so, a VoIP service provider like Nextiva can connect one or more channels to your in-house PBX.

SIP Pricing


Nextiva’s SIP metered plan
Starts at


/mo per user
Make as many calls as you want for less than a penny per minute in the United States, Canada, and Puerto Rico.


Nextiva’s SIP unmetered plan
Starts at


/mo per user
Includes unlimited calling in the United States, Canada, and Puerto Rico.

All the benefits of the cloud minus the hardware costs

Cost savings

Cost savings
like never before

Save up to 70% of your current PBX bill with hosted PBX or SIP trunking. Goodbye, expensive hardware. Hello, cost-effective calling!

Unlimited calling


Unlimited toll-free calling in the United States. Also get local and international calls. No more per-minute charges.

Modern IP PBX


Connecting a hosted PBX to a SIP trunk is easier than via a PSTN. With a cloud phone system, comes real unified business communications.

Advanced business phone system features

Advanced business
phone system features

Voicemail to email, long-distance calling, unlimited inbound and outbound calls, local phone numbers, and more — all with one VoIP phone system.

Keep your existing hardware

Keep your
existing hardware

Keep your existing hardware Use your traditional phone system with an IP-based set-up. Avoid new equipment costs while getting better service.

Your voice and data

Your voice and data
in one place

SIP trunking streamlines your company's technology stack, affording you many proven benefits, including much better call quality and lower costs.

Port your existing number to the cloud. Get started with SIP trunking.

Talk to an expert

Hosted PBX vs. SIP trunking — what's the difference?

Hosted PBX
  • Lower hardware costs since all you need are IP phones, routers, and high-speed internet.
  • Most VoIP providers have a monthly subscription fee.
  • Hosted PBX services let you add new phone lines in a few steps.
  • Your teams can access these phone lines from anywhere in the world.
  • With an online admin portal and easy-to-use features, you don’t need an IT team.
  • Requires minimal maintenance.
On-premise PBX + SIP Trunking
  • Needs on-site IP PBX servers and a SIP trunking service like Nextiva. Higher upfront capital expenditure.
  • SIP trunking charges may be per minute or channel.
  • SIP trunking with traditional PBX may need more on-premise servers.
  • Traditional phones need a LAN connection to the IP PBX.
  • An IT staff member is critical to maintain these on-premise PBX systems.
  • Needs ongoing maintenance.

Here’s what happens when you migrate to Nextiva SIP Trunking

Amazing Service
Dedicated support to oversee migration and setup.
Full analysis
A full analysis of your network and current hosted PBX/legacy PBX system.
Our onboarding team works with you to establish the connections between your IP PBX and Nextiva's service.
Test all inbound
Test all inbound, outbound, and concurrent calls. Troubleshoot any error reports.

Why Nextiva
SIP trunking

8 Nextiva Data Centers

Centralized trunks with an IP core

99.999% uptime

8 points of presence and carrier-grade data centers

Award-winning customer service

Fraud mitigation with access control policies

E911 coverage in the US and Canada


How is Nextiva's PBX SIP trunking service billed?

If you’re wondering how this phone service works in practice from an admin perspective, we send a pro-forma invoice to the email address for the account.

This happens five days before you’re charged the monthly recurring fee. We bill you at the beginning of the month for the new month you are entering.

The only arrears billing happens with the per-minute charges for our SIP unmetered plan or any toll-free calls to your Nextiva SIP trunk account.

Why Are SIP Trunks So Affordable?

If you’re looking at your current PBX bill and comparing it to the above numbers, you already know what makes SIP trunking affordable.
(In that case, you also may want to pull your hair out because of the money you’re throwing away.)

Here are the reasons why SIP trunking is so affordable:
  • There’s no need for expensive POTS (short for Plain Old Telephone Service) lines
  • Lower cost of per-minute calling, even on metered plans
  • Free calls between your employees and offices
  • It maximizes your existing phone system and connecting it to a cloud PBX

Scalability: How Many Channels Does a SIP Trunk Have?

If your company is growing, a traditional phone system will actually punish you for that. Hiring more people means adding more phone lines.

With PRI (Primary Rate Interface), you’re using a traditional phone line to make phone calls. Each PRI circuit allows for up to 23 simultaneous calls. If you need more, you have to buy PRIs in bundles of 23 channels at a time.

Your bill becomes unnecessarily high because you’re paying for a number of channels you don’t need. This system doesn’t give you flexibility or predictability in your recurring or upcoming expenses. It makes scaling particularly difficult if you’re growing your call center.

SIP trunks make it easy to upgrade to a higher plan at any time. You can add more concurrent calls (also known as SIP channels) and phone numbers in real-time.

Zero outages in 2019.
SIP Trunking you can trust.


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