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SIP trunking from BT


Make calls over IP with BT SIP Trunk



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Why BT SIP Trunk is the only choice for business

SIP trunking can help you save money by using your data network to handle all your calls so you no longer need separate phone lines.

BT SIP Trunk channels start at just £8.95 a month, which includes a generous call allowance and free calls between BT SIP Trunks.

Quality is just as important, which is why we offer Quality of Service that ensures calls are prioritised, so quality is not compromised.

You also get more flexibility than with traditional phone lines: you can market your business locally around the country, take your numbers with you if you move, and have your calls diverted to another site in the event of an emergency.

If you’re investing in a data network, SIP trunking makes that investment work harder for you.



Video transcript

Here’s a thing. Just by using an IP connection to make calls, we can help you save money.

Your IP connection carries packets of data: emails, documents, pictures, video, and much more. BT SIP Trunk runs over BTnet, which allows us to create the necessary space for your voice calls to get through.

And you can use that space to make calls, which also come in packets of data. At peak times, data can pile up but BTnet tells the data packets that your voice calls are prioritised and lets them whiz through.

We call this SIP or Session Initiation Protocol (think of it as superior phone calls with BT SIP Trunk).

So what does this mean for your business?

Well, your staff won’t notice a difference: same handset, same quality. But your business will: cost savings, quality calls, and support for all of the SIP components from a dedicated helpdesk.  With BT SIP Trunk, you can make voice calls over your IP connection for a fraction of the cost of traditional phones without sacrificing any of the quality.

Our prices start from just £8.95 per channel per month for your calls and rental. Simple pricing and predictable costs with BT SIP Trunk, for superior IP phone calls.

Contact us to discuss the right solution for you

Arrange a consultation with your BT Local Business specialist now.

9am-5pm, Monday-Friday

This is a sales number only. Please use these numbers for faults and technical queries. 

Book a sales call back

What you'll need for BT SIP Trunk

There are a couple of things you’ll need before you can use BT SIP Trunk.

  1. BTnet

    BTnet is our market-leading leased line. It’s a dedicated, private internet connection that you don’t share with anyone else. And because of that, you get fast, guaranteed speeds and reliability, essential for when you’re using the internet for all of your voice traffic.

  2. Phone system

    BT SIP Trunk works seamlessly with BT IP phone systems, so if you’re buying a new phone system you should consider BT SIP Trunk as an alternative to traditional phone lines. Not only can the cost savings help you maximise your investment, it can also help you make the most of the IP productivity and functionality features of the new phone system.

    But what if you’ve got a traditional phone system and you don’t want to replace it? No problem - you can still have BT SIP Trunk by using a piece of kit called the BT SIP Trunk Gateway. Ask us about it when you call.


Discover the benefits of BT SIP Trunk

Reduced call costs

All BT SIP Trunks come with a generous call allowance, free calls between BT SIP Trunks, and a simple, low-cost pricing structure with no spend commitments.

Prices start from just £8.95 a month, which includes 5000 minutes to UK and international fixed numbers and 500 minutes to UK mobiles.

Make the most of your existing network investment

Using a data network for all your calls means you don’t need separate traditional phone lines.

No line, no line rental. You’ll have just one network, which means it’s also simpler for your IT team to manage.  

Reassurance that call quality will never be compromised

Our Quality of Service (QoS) prioritises your calls over other data. Even if you’re using the rest of your bandwidth, your voice calls will always get through.

With BT SIP Trunk, there’s always an amount of bandwidth dedicated for voice calls. And with call quality just like traditional phone lines, users won’t notice a difference.

Keep people connected

BT SIP Trunk offers more business continuity options than a traditional phone network, so a disaster doesn’t have to be disastrous.

For example, with BT SIP Trunk you can redirect individual extension numbers to numbers of your choice. This delivers much more robust resilience than on a traditional voice network. 

And, with voice calls running over your data connection, your voice will also automatically run over any back-up or resilient BTnet that you have in place for disaster recovery. This can help save money on a separate and dedicated voice back-up option.

Extensively tested (for your peace of mind)

BT SIP Trunk has been extensively tested and works seamlessly with BTnet and BT phone systems. 

Market your business with local numbers wherever you are

You can promote your business locally regardless of your location.

Non-geographic numbers mean that your phone number is no longer tied to the range of numbers available in your local telephone exchange. Open up new business opportunities by creating a local presence, nationally.     

Take your numbers with you wherever you move to

With BT SIP Trunk your numbers stay with you, even if you’re moving premises.

Unlike with traditional phone lines, your numbers are no longer tied to your local telephone exchange so, even if you move to a different part of the country, you can take all of your numbers – and the customers who know them - with you.

Help and support available, whenever you need it

We’ve got a dedicated helpdesk to support you with all elements of your IP solution: SIP trunking, phone system, and BTnet. That means a single point-of-contact; one number and not being passed from one agent to another.

Why BT Business?

Get the right solution for your business from BT Local Business experts
Unbeatable local knowledge, national resources, and personal service
Personal contact helps us get to know you and your business challenges
We’re the leading provider of phone systems in the UK, right on your doorstep


What else do I need so I can have BT SIP Trunk?

You need to have BTnet and a compatible phone system or BT SIP Trunk Gateway.

What phone systems are compatible?

BT phone systems (such as the Avaya IP Office and Mitel MiVoice) are compatible with BT SIP Trunk. But if you have another phone system you could still take BT SIP Trunk by using our BT SIP Trunk Gateway.

Is the call quality as good as on a standard BT line?

Yes. BT SIP Trunk offers Quality of Service (QoS) with voice calls prioritised across the BTnet network, so you can be assured of high quality.  

What happens to my calls in the event of a disaster?

With BT SIP Trunk, if for any reason the service fails (e.g. network failure or natural disaster) then calls to BT SIP Trunks can automatically re-route to other phone lines or mobiles. 

If I have BT SIP Trunk and move premises can I take my phone numbers with me?

Yes, the numbers are IP-based and not tied to a telephone exchange, so you can have any geographic phone numbers and take them with you wherever you move. 

Can I discuss my options with someone in person, rather than on the phone?

Yes, we’ll put you in touch with your Local BT Business and they can arrange to visit you.



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