Can You Get VoIP Without a Provider?

How Does VoIP Without a Provider Work?

VoIP sends voice as data over the internet rather than through a traditional phone line. That part alone does not need a provider. Two people using compatible softphone apps, or a peer-to-peer calling tool, can talk to each other with no telecoms company involved.

In practice, this only covers internal or app-to-app calling. A self-hosted PBX system, such as Asterisk, FreePBX, or FreeSWITCH, can run a business's entire internal call-handling setup without outside involvement. But to place or receive a call from a customer's mobile or a supplier's landline, that self-hosted system still needs a SIP trunk plugged into it. Without that connection, calls stay trapped inside the internal network.

Common ways businesses try to reduce provider involvement include:

• Running a self-hosted PBX for internal call routing and extension management
• Using app-to-app calling for team communication that never touches the phone network
• Adding a SIP trunk from a provider only for external calling, keeping the rest of the system self-managed
• Using free-sounding VoIP tools, which are still providers in function even without the traditional branding
  

What Does a Provider Actually Do?

Even in a self-hosted setup, a provider is still doing several things behind the scenes: assigning and porting phone numbers, connecting the system to the wider phone network, maintaining call quality and uptime, and meeting regulatory requirements around emergency calling and number ownership. Self-hosting the PBX can cut costs and add flexibility, but it does not remove the need for a provider at the connection layer. This connection is provided by a SIP trunk, or avoided entirely with a fully hosted phone system where the provider manages everything.



In our experience, the businesses that ask about going provider-free are usually weighing up an existing on-premises PBX, and the deciding factor is almost always who carries the security and fraud risk, not the monthly cost.

What Are the Practical Trade-Offs?

More Control, Same Dependency

A self-hosted PBX gives a business full control over call flows, extensions, and internal features. It does not reduce dependency on a provider for the part that actually connects calls to the outside world.

Lower Cost, Higher Setup Effort

Self-hosting can lower ongoing software costs, but the trade-off is more setup and maintenance work, either in-house or through IT support. As a rough benchmark, fully hosted VoIP in the UK typically runs from around £10 to £30 per user per month in 2026, already covering the phone network connection, security, and support. A self-hosted PBX avoids that recurring per-user fee but shifts the cost into hardware, software licensing or setup, and ongoing IT time, plus a separate SIP trunk to actually reach outside numbers.

Not for Customer-Facing Lines

App-to-app or internal-only VoIP works well for team calls but is not a workable substitute for a business phone number that customers and suppliers need to reach.

The Risk of Going It Alone

Self-hosting also shifts security responsibility onto the business. There have been real cases of small UK companies with unmaintained on-premises PBX systems being hacked and left with tens of thousands of pounds in fraudulent call charges, often discovered only after a weekend or holiday closure. With a provider-managed system, that security and monitoring is built in as part of the service. This is one of the clearest practical reasons a provider is worth the cost, even for businesses that could technically self-host the rest of the system.

Here is how self-hosting compares with a fully hosted VoIP service:

Is a Provider Required by Default?

For any VoIP setup that needs to call or be called by standard phone numbers, yes, a provider is required by default. Building a workaround to avoid a provider is unlikely to be worth the effort, especially with the PSTN switch-off approaching.

The UK PSTN and ISDN network will be switched off on 31 January 2027.

Businesses still on legacy analogue lines will need to move to a provider-based VoIP or hosted system before then regardless, so now is the point to choose the right setup rather than build around avoiding a provider.