O2 Business SIP Trunking
O2 Business SIP Trunking: A UK-focused SIP service with resilient connectivity, numbering controls and per-minute billing. Ranked #27 of 28 in SIP Trunking Providers by our editors (6.6/10); pricing: Paid; best for UK organizations using resilient SIP access.
At a glance
- Editor score6.6 / 10
- PricingPaid
- Best forUK organizations using resilient SIP access
- Free planNo
- Emergency callingYes
- Facts checked19 Sep 2026
Where it wins
- Multiple access options, including public internet, JANET, Ethernet and O2 Gateway
- UK number provisioning, DDI management and number porting
- Resilience, emergency calling, fraud management and call barring
Where it doesn't
- No free plan is available
- Billing is based on voice minutes and domestic call bundles
- Primarily suited to PBX-based telephony environments
Our verdict on O2 Business SIP Trunking
O2 Business SIP Trunking connects business phone systems to the public telephone network through SIP. It is aimed at UK organisations replacing or consolidating ISDN and other legacy voice connections, particularly those that need geographic numbering, UK number porting and support for PBX-based telephony. Connectivity can run over the public internet, JANET, dedicated Ethernet or O2 Gateway, giving organisations several deployment paths for their voice service.
Resilience is a central strength. O2 documents active-standby, resilience and load-sharing configurations for SIP endpoints, alongside configurable emergency call diverts. The service also supports calls to 999 and 112, fraud management, call barring and DDI management. These features make it a practical fit for organisations that need continuity planning and tighter control over business calling rather than a basic internet-based voice connection.
The pricing model is based on voice minutes, with domestic call bundles also available. The published offer includes paid service rather than a free plan, and organisations should assess the fit between minute-based billing and their calling patterns. O2 Business SIP Trunking suits UK organisations with an existing or planned PBX, a need for number management and a preference for configurable connectivity and resilience. It is less suitable for teams seeking a standalone hosted phone system, a free tier or a narrowly defined single-network deployment.
Your product? Our editors can test O2 Business SIP Trunking in depth and publish a review, labelled as paid · from $149/mo →
O2 Business SIP Trunking pricing
O2 Business SIP Trunking fact sheet
| Free plan | No |
|---|---|
| Paid from | Not verified |
| Pricing model | Per-minute |
| Concurrent channels | Not verified |
| Number porting | Yes |
| Emergency calling | Yes |
| Toll-free numbers | Yes |
| Encrypted signaling | Not verified |
| Integrations | 5 integrations: PBX, Public internet, JANET, Ethernet, O2 Gateway |
| Pricing | Paid (source) |
| Website | o2.co.uk |
| Facts checked | 19 Sep 2026 |
O2 Business SIP Trunking integrations
O2 Business SIP Trunking lists 5 integrations on its own site.
- PBX
- Public internet
- JANET
- Ethernet
- O2 Gateway
Alternatives to O2 Business SIP Trunking
- IPComms SIP TrunkingA low-cost SIP trunk with encryption, E911, failover, and broad PBX integrations.9.4
- Telnyx SIP TrunkingLow-usage SIP trunking with API setup, calling features, and pay-as-you-go pricing.9.3
- BulkVS SIP TrunkingA low-cost SIP option for North American numbers, PBXs, and carrier workflows.9.2
See all O2 Business SIP Trunking alternatives →
Used O2 Business SIP Trunking? Be the first to review it
The editor score above is our own research. What this page doesn't have yet is a reader's view — what you used O2 Business SIP Trunking for, what worked and what didn't. No stars are seeded and no review is paid for; an editor reads every one before it appears.
Write a reviewTwo minutes · verified accounts only · read by an editor before it appears
Featured on iTechGuides
O2 Business SIP Trunking is listed in our SIP Trunking Providers directory. Add the badge to your site — it links back to this page.
<a href="https://www.itechguides.com/products/o2-business-sip-trunking/"><img src="https://www.itechguides.com/best/badge/o2-business-sip-trunking.svg" alt="Featured on iTechGuides" width="230" height="46"></a>
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update