SIP Trunking Pricing Guide: Complete Cost Analysis for 2025

SIP trunking is the ideal communications technology for many businesses, offering cost savings, easy scalability, and high-quality voice calls. However, understanding SIP trunking pricing can be complex due to the multitude of providers, pricing models, and hidden setup fees.

Some SIP trunk service providers advertise low monthly fees but surprise with high per-minute charges, additional feature costs, and high setup costs. You don’t need the cheapest plan, but the best value with predictable billing.

This comprehensive pricing guide explains SIP trunking costs. We’ll explore different trunking pricing models, show you how to calculate your expected costs, compare top providers, and find the right model for your budget and business needs.

Key Takeaways

In a snapshot, how much does a SIP trunk cost?

An unlimited SIP trunk channel typically costs $15 to $25 per month or $0.005–$0.02 per minute for usage-based pricing plans. The total monthly price depends on the number of SIP channels required, plus phone number (DID) and emergency service charges.

• Pricing models: Most providers use either a metered (pay-per-minute) or unmetered (flat-rate per channel) model, with some offering pay-as-you-go options.
• Key cost factors: In addition to the channels, the number of phone numbers, call destinations, toll-free numbers, and other additional features influence your final price.
• Calculating costs: You can calculate your monthly SIP trunk costs by determining the number of concurrent calls you need and choosing a plan that matches your actual usage and billing cycle requirements.
• Comparing providers: Always compare the estimated total costs of different providers in a trunk pricing comparison, not just the price per channel.

What Is SIP Trunking? (A Quick Refresher)

Session initiation protocol (SIP) trunking is the technology for establishing and managing voice calls over the internet. A SIP trunk is the virtual connection that connects your office phone system (a local PBX) to the internet and the public switched telephone network. It’s a digital replacement for your traditional copper lines and PRI lines.

Why Is a SIP Trunk Better than Traditional Systems?

Many businesses are moving from older primary rate interface (PRI) lines and traditional TDM circuits to SIP trunks. Here’s how the systems compare and why SIP is better and more cost-effective.

How SIP Trunking Is Priced (Models, Factors, and Ranges)

Your SIP trunking bill is determined by the pricing model you choose and several other important factors. Understanding these factors that influence account pricing is the first step toward getting volume pricing and the best rates.

Main SIP trunk pricing models

• Metered plans (pay per-minute): You pay a low monthly connection fee and are billed for each minute of inbound calls and outgoing calls. This approach can be cost-effective for businesses with low call volumes, but it can become expensive and unpredictable during busy periods.
• Unmetered/unlimited plans: This is the most popular SIP trunking model. You pay a fixed monthly price per channel, which includes unlimited calling to the US and Canada. Budgeting is easy and ideal for businesses with medium to high call volumes through predictable billing.
• Pay-as-you-go models: Some providers offer flexible pricing where you only pay for what you use, making it easier to manage campaign costs and variable usage patterns.

What is wholesale SIP trunking?

You’ll also come across the term “wholesale SIP trunking.” This is a high-volume, low-margin service with volume discounts designed for IT providers, resellers, and large enterprises that manage their own telecommunications infrastructure. For most businesses, standard plans from VoIP providers are the right choice.

Key cost factors that influence your SIP trunking bill

Before choosing a SIP trunk service, you should know the factors that affect SIP pricing and how they affect the total cost.

• Number of SIP channels: The more concurrent calls you need, the more channels you’ll pay for. This is the main factor in your base cost.
• Direct telephone numbers: Each direct inward dialing number (DID) and local number can cost between $1 and $2 per month. A one-time fee may apply to porting your existing numbers.
• Toll-free numbers: Incoming calls to a toll-free number usually have their own per-message charges, even with unlimited plans. Some providers require toll-free verification for certain services.
• Long-distance and call destination: With metered plans, international calls are billed at different rates depending on the country. Unlimited plans typically only cover calls within the US and Canada.
• Important add-ons: Beware of per-message charges for important services. Some providers charge extra for E911 service (legally required), caller ID (CNAM) transmission, call recording and analytics, call routing features, and fax services for existing fax systems.
• Setup fees: Some trunking providers charge one-time setup fees to activate your account or connect your PBX through their web portal.

Consider all these factors when planning your budget. Compare prices from different providers before choosing a SIP trunk plan, including monthly base fees, per-minute charges, and additional features you might need.

SIP Trunk Pricing Calculator: How To Estimate Your Monthly Cost

You don’t need a complex tool to get a reliable cost estimate. Follow these simple steps.

1. Calculate your required channels

The most important factor is the maximum number of concurrent calls.

Rule of thumb: A good starting point is one channel per 3-4 employees. For an office with 30 employees, you’ll likely need 8-10 SIP channels. Better yet, check your current phone provider’s bill for your peak number of simultaneous calls and actual usage patterns.

2. Choose your pricing model

Look at your calling patterns and billing cycle preferences.

• Choose “metered” if your call volume is low (e.g., less than 1,000 minutes/month) and you rarely make long-distance calls.
• Choose “unmetered” if you have medium to high call volume and want predictable billing with unlimited calling.

3. Add up your numbers and features

List all the extras you’ll need through your web portal. How many individual phone numbers? Do you need toll-free numbers? Will you need call recording or fax services for incoming faxes and outbound faxes?

4. Create a sample estimate

Let’s calculate the estimated cost for a 40-person office that needs 12 channels and 40 phone numbers, choosing a typical unmetered plan.

• 12 Channels on Unmetered Plan (@ $24.95/channel): $299.40/month
• 40 Phone Numbers (DIDs) (@ $1/number): $40.00/month
• E911 Service (@ $1.50/number): $60.00/month
• Estimated monthly total: $399.40

Quick Checklist: Questions To Ask Every SIP Provider

Before contacting sales or signing a contract, use this checklist to get clear answers and avoid hidden fees.

Pricing and fees

• What is the total cost per channel per month?
• Are there mandatory setup fees, activation, or number porting costs?
• What are the exact per-minute rates for international countries I call frequently?
• Is E911 service included in the channel price, or separate per-number charges?
• Do you offer volume discounts for larger accounts?

Service features

• What call routing options are available?
• Do you support call recording capabilities?
• Can you handle incoming and outgoing calls efficiently?
• What fax services do you offer for our existing fax needs?

Reliability and support

• What is your network uptime guarantee or Service Level Agreement (SLA)?
• What kind of customer support is included (e.g., 24/7, phone, email)?
• Can I manage my account through a web portal?

Contracts and scalability

• What are the contract terms (e.g., month-to-month, annual)?
• How quickly can I add or remove SIP channels as needs change?
• Do you offer pay-as-you-go flexibility?

SIP Trunk Providers and Pricing Comparison

SIP trunk pricing and features can vary a lot across the market. Some providers offer clear and transparent pricing online, while others may need custom quotes from sales. That said, here’s key SIP pricing information and a comparison of the best SIP trunk providers for businesses.

How to get the best SIP trunk pricing

Researching providers is half the battle. Follow these best practices to choose the right provider and get optimal rates.

• Choose the right plan: Don’t overpay for unlimited calling if your usage is low, and don’t risk high bills with pay-as-you-go if your usage is consistently high.
• Bundle services: Many VoIP service providers offer volume discounts if you bundle SIP with other services, such as video conferencing or contact center solutions.
• Negotiate contracts: When you contact sales, you may get better deals for longer-term contracts or by foregoing features you don’t need.
• Review actual usage: Monitor your billing cycle usage quarterly. If you regularly use fewer SIP channels than you pay for, ask your provider to adjust your plan through their web portal.
• Consider volume pricing: Larger businesses can negotiate better rates based on their concurrent call requirements and overall account message quantity.

Is SIP Trunking Right for You? (vs. Hosted VoIP)

Although both systems use VoIP, SIP trunking differs from a hosted, all-in-one business phone system.

SIP trunking is designed for businesses that already own and manage an on-premises PBX. It’s a technical solution connecting existing hardware to the cloud while maintaining your current setup for handling concurrent calls.

Hosted PBX or hosted VoIP is an all-in-one solution where the provider manages everything in the cloud. It’s ideal for businesses without their own PBX that want a simple, fully managed phone system.

If you’re considering hosted PBX and SIP trunking, here are the key differences and comparisons you should keep in mind:

• Cost of initial setup: Hosted PBX costs less if you have no on-premises PBX equipment; SIP trunking is more cost-effective if you already own equipment.
• Ongoing costs: Expect to pay between $15 and $60 per phone line per month, depending on your chosen pricing model and actual usage.
• Maintenance: Your VoIP provider handles maintenance and updates for hosted PBX systems.
• Company size: Hosted PBX systems work best for small businesses. SIP trunking excels for high-volume call environments requiring multiple concurrent calls.
• Call quality: Hosted PBX suits moderate call volumes, while SIP trunking handles high volume much better with proper PBX configuration.
• Advanced features: Both can offer call recording, call routing, and integration with existing fax systems, but implementation varies.
• Security: SIP trunking offers equivalent security features at a technical level, but a hosted PBX can be connected to Single Sign On, and call logs are readily available to IT admins.

SIP trunking typically requires that businesses be technical, and it can become complicated relatively quickly. It may also lack customer support that IT managers (and users!) need, though this depends on the provider.

It’s worth considering that the cloud phone system by Nextiva can offer all the advanced features, call uptime, customer support, and ease of use that growing businesses need.

Choose Nextiva for Simple, Transparent SIP Trunking

Get reliable, cost-effective SIP trunking that connects your existing PBX to the cloud – with clear voice quality, easy scalability, and hassle-free service.

With Nextiva’s affordable SIP trunk pricing, you can modernize your phone system without replacing your hardware. Our straightforward plans include free local and toll-free numbers, backed by our 99.999% network availability and award-winning 24/7 support.

Easily manage your account, monitor actual usage, and adjust your SIP channels as needed through our web portal. With predictable billing and no hidden setup fees, you can focus on your business while we take care of your communications infrastructure.

SIP Trunk Pricing FAQs