Cloud PBX or SIP Trunk: What to Choose for Business in 2026

Both solutions use the internet to transmit voice, and the terms are often mixed up. But these are different models with different economics, control levels, and complexity. The choice between them determines how telephony will work for years to come.

What's the difference

Cloud PBX is a ready-made phone system in the provider's cloud: queues, IVR, call recording, integrations — all included in the subscription. You manage settings through the admin panel; the provider is responsible for infrastructure.

SIP trunking is the road to the telephone network for your own PBX (on-premise or cloud). You control the switch, routing, and integrations; the provider ensures connectivity with the outside world and numbers.

A simple analogy: cloud PBX is a furnished apartment with maintenance; a SIP trunk is your own house where you decide how everything is arranged.

When to choose cloud PBX

The company has no own PBX and no desire to administer one;

fast launch is needed — from request to first calls in a day;

ready-made out-of-the-box features matter: IVR, queues, recording, mobile apps, CRM integration;

the team is distributed: employees connect from anywhere via softphone.

Economics: payment per user per month. For a team up to 30–50 people, this is usually cheaper and simpler than maintaining your own switch.

When to choose SIP trunking

A PBX already exists with money and configuration invested;

full control over routing, codecs, and security policies is important;

simultaneous call volume is significantly lower than headcount — paying for channels is more profitable than paying per user;

there are specific integrations, a call center on your own platform, or elevated compliance requirements.

Economics: payment for channels. A company with 30 employees and 8 simultaneous calls at peak pays for 8 channels — savings compared to user licenses are obvious.

Hybrid scenario

In practice, many companies combine both: cloud PBX gives employees a convenient interface and features, while a SIP trunk provides cost-effective connectivity with the external network and international destinations. This scenario combines management simplicity with per-minute cost control — and is increasingly becoming the standard for growing businesses.

Decision checklist

Do you have your own PBX and competencies to support it?

How many simultaneous calls do you have at peak — and how many employees?

How critical are ready-made features versus configuration flexibility?

Are international expansion and multi-market operations planned?

Answers to these four questions in most cases clearly point to a model — or to a hybrid.

Proton offers both solutions: cloud PBX with launch in one day and SIP trunks for your own infrastructure. Tell us about your current setup — we will help calculate the economics of both models on your numbers and choose the optimal one.