Take your first step towards cloud-based communication.

The NFON SIP Trunk lets you choose how you want to communicate.

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Features: Set your business up for success.

With cloud phone systems, there is no need for conventional telephony hardware anymore. It can be implemented and maintained more easily and at lower cost. At the same time, it gives you the flexibility to scale the number of users up and down according to your business needs.

Full telephony features.

Enhance security by blocking outgoing calls to selected destinations, detect fraud with real-time call monitoring, and ensure high availability with a second PBX for efficient call load distribution across locations.


  • Block calls: Block outgoing calls to selected destinations.

  • Detect fraud: Security is a priority. We’ll monitor calls to prevent fraud on your platform.

  • High availability: Connect a second PBX to forward incoming calls, ensuring even call load distribution across locations for improved team efficiency.

Flexible number routing.

Flexible allocation of telephone numbers without having to purchase new blocks. Numbers from one block can be assigned to different trunk sets, providing more control and lower costs

Instant access self-service hub.

Everything you need at your fingertips. Feel confident setting up and managing SIP Trunks by yourself

Integrate PSTN connectivity and integration.

Integrate PSTN connectivity with Genesys Cloud/CCHub for seamless inbound and outbound contact center calling, and connect Microsoft Teams* to PSTN with full telephony features through Operator Connect or Direct Routing.


  • Genesys Cloud/CCHub: Allows PSTN connectivity, along with inbound and outbound calling for your contact centre.

  • Microsoft Teams* Integration: Connect Microsoft Teams* with PSTN and all the standard telephony features via Operator Connect or Direct Routing

Discover the benefits.

Unlock exclusive cloud solutions.

Access exclusive cloud solutions not available with other SIP Trunks.

Stay connected.

Remain connected with on-premise systems.


Unified telephony with Microsoft Teams*.

Seamless integration of telephony and unified communications through Microsoft Teams* integration.


Achieve cost efficiency.

Enjoy cost-efficiency by unlocking cloud benefits.


Talk more, spend less.

Favourable telephone tariffs.


Get in touch

All the features you need, always available.

Call blocking

Block outgoing calls to selected destinations for enhanced security.

Fraud detection

Our system monitors calls to prevent fraud on your platform.

High availability

Connect a second PBX for redundancy and even call load distribution across different locations.

Backup systems

Ensure constant coverage with backup systems that kick in when your PBX is unavailable.

Self-service portals

Set up and manage your SIP trunks confidently with everything at your fingertips.

Conference services

Host audio conferences with up to 50 participants easily.

Genesys Cloud/CCHub integration

Enable PSTN connectivity for your contact centre with

inbound and outbound calling.

Microsoft Teams* Integration

Connect Microsoft Teams* with PSTN and standard telephony features via Operator Connect or Direct Routing.
Access SIP Trunk Flexx demo

Why SIP Trunk Flexx?

Need an intermediary?

NFON SIP Trunk Flexx is the solution if you have existing maintenance contracts for your onsite PBX.

Need to cut costs?

Consolidating voice and data networks into a converged IP infrastructure decreases maintenance costs and more.

Need to upgrade… later?

With a SIP Trunk provider you keep all options open for full cloud services, a new world of communications.

SIP Trunk Flexx sets your people free.

SIP Trunk Flexx is a flexible VoIP telephony solution that allows you to configure multiple telephone systems and PBX endpoints, including Microsoft Teams. It enables seamless number routing for your ported MSN numbers and other number blocks to any PBX on your SIP trunk.

Easy.

SIP Trunk Flexx provides a flexible, easy setup for your business. Configure multiple phone systems and PBX endpoints, like Microsoft Teams*, all within a single trunk setup.

Flexible.

With the number routing service, effortlessly direct your ported MSN numbers and other number blocks to any PBX on your SIP Trunk, offering unmatched flexibility for your setup.

Reliable.

NFON provides a fully redundant architecture, end-to-end data security, and in-house managed voice services. This approach maximizes uptime, ensuring 99.9% platform availability, so you’re always accessible to your customers.

Good reads.

SIP Trunk Flexx One-pager SIP Trunk Flexx Product Sheet

Jump into the cloud - upgrade now!

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