Comparison
SIP Trunk vs Hosted PBX: Control, Cost and Scale
A SIP trunk connects a phone system you run to the public network. A hosted PBX rents you the phone system as a service, usually per user. The choice comes down to who owns the PBX and how you want to pay.
Short answer
Side by side
SIP trunk and Hosted PBX compared
| SIP trunk | Hosted PBX | |
|---|---|---|
| What you get | Voice connectivity for your own PBX | A complete phone system run by the provider |
| Who runs the PBX | You | The provider |
| Pricing model | Per minute from prepaid balance | Per user per month, often with bundled minutes |
| Scales with | Concurrent calls | Number of seats |
| Routing control | Full: dial plans, tiers, tech prefixes | Limited to the provider’s settings |
| Dialers and call centres | Built for high concurrency | Often capped or prohibited |
| International routes | Choose CLI or non-CLI per destination | Fixed, usually premium only |
| Setup effort | PBX config, firewall, codecs | Plug in phones or install an app |
| Vendor lock-in | Low: change trunks in minutes | Higher: numbers and config live with provider |
Which one fits
When each option makes sense
Choose SIP trunk when
- You already run 3CX, FreePBX, Asterisk, FusionPBX or another PBX.
- You operate a dialer, contact centre or softswitch with many concurrent calls.
- You resell voice and need to set your own rates and routing.
- You want to mix CLI and non-CLI routes or several carriers.
- Your call volume is high relative to your headcount.
Choose Hosted PBX when
- You have fewer than about 20 users and no in-house telecom skills.
- You want a fixed monthly cost per person and are happy with bundled minutes.
- Most calls are domestic and features matter more than per-minute cost.
- You do not want to patch, back up or secure a PBX yourself.
Cost
Illustrative monthly cost for a 50-agent outbound team
Sample figures for 50 agents placing around 150,000 outbound minutes a month. Real prices depend on destinations and features.
| Item | SIP trunk + own PBX | Hosted PBX |
|---|---|---|
| Seats / licences | $0 – $300 (PBX licence) | $1,000 – $1,750 |
| Server or cloud VM | $40 – $120 | Included |
| 150,000 minutes | $1,050 – $1,800 | Often over the bundle |
| Overage minutes | Same per-minute rate | Premium rate per minute |
| Typical monthly total | $1,090 – $2,220 | $1,500 – $3,500+ |
Sample figures only, not a quote. SIP minute rates start from $0.007 per minute and are placeholders until current rates are published.
Moving over
Moving from a hosted PBX to your own PBX and a SIP trunk
- 01
Pick the PBX
Choose a platform such as 3CX, FreePBX or FusionPBX and size the server for your peak calls. - 02
Rebuild call flows
Recreate extensions, queues, IVRs and voicemail, then connect the SIP trunk and test. - 03
Port numbers
Request a port of your numbers from the hosted provider, or add new DIDs and forward the old ones. - 04
Cut over
Move users in groups, watch CDRs and quality for a week, then end the hosted contract.
FAQ
Common questions
Further reading:
Can I use a SIP trunk with a hosted PBX?
Some hosted PBX providers allow you to bring your own trunk, which can lower international or high-volume costs. Many do not, so check the provider’s terms first.
Is a hosted PBX more secure?
The provider handles patching, which helps small teams. A self-run PBX with IP authentication, strong passwords and a firewall is equally secure, but you are responsible for keeping it that way.
Which is better for a call centre?
Usually a SIP trunk. Call centres need high concurrency, predictive dialing and per-destination routing, and hosted PBX plans are rarely priced or licensed for that.
Do I need a technician to run my own PBX?
You need someone comfortable with networking and the PBX’s admin panel. Our setup guides cover the trunk side for the most common platforms, and the NOC answers technical questions 24/7.