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SIP Trunking

Evolve voice services and make cost savings compared to ISDN

Reliable, secure and cost-effective


SIP Trunks are more cost effective than traditional connections to the public telephone network, such as ISDN.

They’re more flexible, easily adapting to changes in demand, or resilience requirements.  And they’ll flex, as your organisation or locations change.


Get in touch

10+ employees, Enterprise and Public Sector

Call us at0800 955 5590

Why choose SIP Trunking?

Simplify your spend

Choose from our three easy-to-understand pricing options so that you’ll always be on top of your spending.

Cut cost and complexity

Move to SIP Trunking and you’ll be able to centralise and rationalise your telephony estate. It doesn’t just make life simpler, it also reduces the cost of maintaining numerous PBXs.

Scale on-demand

Whatever your business need, we give you the flexibility to add and remove capacity during busy periods, for campaigns or special events.

Get flexible phone numbers

Keep the same geographic numbers when you move office. There’s no ongoing call forwarding costs and no hassle of producing new stationery or updating online details.

Manage your inbound calls

Add on the optional SIP Trunk Call Manager to manage inbound calls to all your geographic and non-geographic numbers from our easy to use portal and mobile app.

Enhanced resilience

With options for complete active-standby or loadsharing between different sites you gain greater certainty that your telephony service will be there when you need it.

SIP Trunking from O2

Replace ISDN and traditional phone lines

Which package is right for you?

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Price per minute

SIP Trunking

Perfect if you have fairly stable demand levels. Pay for only what you use –…

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    No monthly commitment and no need to buy a minute bundle
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    Pay for all calls at an agreed PPM rate
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UK domestic bundle

SIP Trunking

Ideal for maintaining a consistent spend on your domestic landline…

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    Inclusive calls to 01, 02 and 03 landline numbers
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    Subject to a 5,000 minutes per channel, per month fair usage policy
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UK domestic and mobile bundle

SIP Trunking

Good for organisations that have recently expanded their mobile…

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    Inclusive calls to 01, 02 and 03 (landline) and 07 (mobile) numbers
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    Three-year contract term 
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    Subject to a 2,000 minutes per channel, per month fair usage policy

A little bit more info

O2 SIP Trunking Product sheet for medium sized businesses

Read more about O2 SIP Trunking for medium sized businesses 

O2 SIP Trunking Product sheet for larger businesses

Read more about O2 SIP Trunking for larger businesses.

O2 SIP Trunking tariff document

Get more information the O2 SIP Trunking tariff here including voice termination rates

O2 SIP Trunking price list.

Download the latest O2 SIP Trunking price list, including pricing for SIP channels, New numbers, Porting Numbers and the minute bundle options.

SIP Trunk Call Manager product overview

Read our SIP Trunk Call Manager product overview here