SIP trunk pricing guide for small businesses

Trying to decide if SIP trunking is cost effective for your small business? Learn all about SIP trunk costs here.

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The price of SIP trunking for a business will comprise several contributing costs, such as an installation fee (£300-£700), a monthly rental fee (£50-150), channel cost (£3-£150), and call charges (variable).

It will also depend on different factors specific to the business, like how many users it has to cater for, how much bandwidth you need, and how many locations the system will be used in.

Either way SIP trunking is an effective way to cut call costs for your business. But the important question is, which providers will offer the best value for money in offering this service? We’re here to help you get that answer.

We’ve put together this pricing guide, to help you budget for the cost of setting up a SIP trunk system for your small business. This includes set-up costs, installation fees, and call charges.

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Average SIP trunk costs for small UK businesses

Below is a summary of the average costs involved when setting up a SIP trunking telephone system for your small business.

SIP Trunking Costs:

Key ElementAverage cost
Monthly service rental£50-£150 per month
Channel cost£3-£150 per month
Call chargesVariable

Pricing is correct as of 17th August 2021

The table below outlines the cost components of SIP trunking in further detail and gives an indication of what you could expect to pay.

These are approximate figures, as the exact amount will depend on your specific business requirements.

They are based on data from Spitfire, and other established SIP providers, to give you an idea about the average SIP trunk costs in the UK.

Call charges (between SIP trunks from same provider)£0Calls made to and from SIP trunks by the same provider are free, e.g. between multiple premises in the same business
Call chargesVariable – charged on a pence per minute basisThe cost of making calls – usually offered as a pay-as-you-go or call bundle package
Phone line costs£0SIP trunking operates through one network (the internet connection), so there aren’t any physical lines to pay for
Number portingVariable – often on a per number basisTransfer your existing phone numbers and/or set up staff who are currently using an extension with their own direct line
Channel cost£3 through to £150+ per monthCharges vary depending on the number of channels your business requires. The cheapest cost is for one SIP line, whereas a call centre or other business that may need 10, 30 or more lines (for example) can expect to pay a much higher amount
Installation fee£300-£700, depending on number of SIP trunksTo connect your phone system to SIP trunk services. The more SIP trunks your business requires, the higher the installation fee is going to be
Monthly rental fee£50-£150, depending on number of SIP trunksThe cost to use the service each month – the more SIP trunks required, the more expensive the monthly rental fee

Pricing is correct as of 17th August 2021

What influences call charges?

The price you pay per call is comprised of several elements, such as:

  • Line charges (but remember SIP trunking doesn’t use phone lines)
  • Per-minute call fees
  • System maintenance
  • Type of numbers called e.g. landline, mobile, international
We get it, there are plenty of providers offering similar products, and it can be a pain reading through reviews and analysing comparison tables...

So why not answer a few simple questions about your business using our incredible comparison tool, which will tailor your specific needs to the best SIP trunk providers available.

You’ll receive quotes, additional product information, and find it a lot easier to select the right provider for you. The best part is, it takes just minutes.

What other SIP trunk costs should you consider?

In addition to the standard elements of SIP trunking, there are some other features and functions that you might wish to incorporate into your business phone system, which may incur extra charges. These include:

  • Disaster recovery plans – are they included, or do you have to pay extra? These are usually available as part of the package, but the options (and therefore the costs) may vary depending on the complexity of your company’s requirements.
  • Fraud services – these are either available as part of the package or as an add-on feature. You should have some level of fraud protection so that you’re covered against fraudulent calls made from your system or account, such as expensive international calls.
  • Integrated communications – if you wish to use SIP trunking to unify your communications across your business (e.g. phone, messaging, email), this is likely to require extra expenditure.

On-premises vs hosted SIP trunking

You’re likely to come across these terms when reviewing SIP trunking options for your business. But what do they mean, and what are the cost implications?

On-premises SIP trunking
(Best for large businesses)
Hosted SIP trunking
(Best for small businesses)
- Maintained on your site
- Kept with the server
- Hardware required
- More expensive to set up
- You own the system
- You are responsible for maintenance costs
- Features available include messaging, call forwarding, voicemail etc.
- Maintained by an external provider via the cloud
- Completely internet-based
- Features available include messaging, call forwarding, voicemail etc.
- Cheaper to set up as you rent the system
- Charges can vary on an ongoing basis
- Provider responsible for maintenance

While both options are available, most small businesses are likely to opt for hosted SIP trunking.

This is because it’s easier, cheaper and requires less space.

Do you need a phone system to support a larger team of 5 staff of more? Will you in the future?

SIP trunking systems offer flexibility and scalability as well as the potential to save on costs, making it a perfect solution for managing the communications of growing teams.

If these functions would benefit your business, simply answer a few simple questions using our free comparison tool, and we’ll provide you with bespoke SIP trunking quotes from providers that match your business needs.

SIP trunk pricing factors

While we can’t in this article give you an exact figure of how much SIP trunking will cost your business (although our comparison tool can), we can suggest you think about the following questions when calculating SIP trunk costs.

  • How much bandwidth do you have/need to run your phone system?
  • How many users does the system need to cater for?
  • How many locations will it be used in?
  • Do you already have an IP PBX, or will you need to rent/buy a gateway to use SIP trunking?
  • Are your business’ phone handsets compatible with IP and SIP?
  • How much customer support and technical assistance will you require?

Now, let’s take a closer look into the different factors that can affect SIP trunk pricing that you should consider when creating your budget:

  • Plan prices – you’ll need to decide between a metered (pay per minute) or channel-based (pay per channel) package.
  • Set-up fees – sometimes this is offered for free, although it’s also possible that you’ll need to account for a one-off fee to get started.
  • Geographic area – whether you need to make and receive calls to mobiles, as well as national or international phone numbers, will affect the price you pay.
  • Scaling channels – if you need to add or remove channels, there’s likely to be a charge for this, so be sure to factor this in when working out your SIP trunk costs.
  • Additional elements – special numbers (such as those used for emergency or freephone calls), and number porting (to transfer current numbers) are some examples of services that may be charged in addition to the standard plan price.
  • Reporting – some providers may be able to offer you reporting analysis to examine how much bandwidth your system uses, granting you opportunities to make further gains. Check if this service is free, or if it incurs an additional charge.
  • Hardware costs – if you do need to purchase hardware (such as new handsets/phones) to work with SIP trunking, consider the amount of time needed to pay this off versus the monthly charges you’ll need to account for too.

Note that SIP trunking relies on a strong internet connection, so be sure to factor this into your costs. Read our page on the best broadband for small businesses for more inspiration.

Want to quickly compare bespoke quotes from the best providers in the UK?

You’re already sold on SIP trunking for your business, but now you just need to ensure you get the best possible deal for your small business, as the last thing you want is to be tied into an expensive contract with a poor provider.

This is where we come in. Our free comparison tool will match you with the right provider for your business needs, providing you with direct SIP trunking quotes that you can easily compare.

All you have to do is fill out a few details, and we will do the rest.

Next steps: Comparing SIP trunking quotes quickly and easily

You now will feel more confident about SIP trunk pricing and related costs, including how much it’s likely to cost you to actually set up SIP trunking for your small business.

The next step is to pick the right provider, and it’s vital you find a system that matches your business requirements and offers great value in the process.

By using our comparison tool, you’ll be guaranteed a selection of reliable quotes from some of the UK’s top SIP trunk providers. From there you can compare them easily, receive additional information, and make a decision that’s best for you and your business. It’s simple, just fill out the form to receive personalised quotes and you’ll be on your way. is reader-supported. If you make a purchase through the links on our site, we may earn a commission from the retailers of the products we have reviewed. This helps to provide free reviews for our readers. It has no additional cost to you, and never affects the editorial independence of our reviews.

Written by:
Ross has been writing for Startups since 2021, specialising in telephone systems, digital marketing, payroll, and sustainable business. He also runs the successful entrepreneur section of the website. Having graduated with a Masters in Journalism, Ross went on to write for Condé Nast Traveller and the NME, before moving in to the world of business journalism. Ross has been involved in startups from a young age, and has a keen eye for exciting, innovative new businesses. Follow him on his Twitter - @startupsross for helpful business tips.
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