What is a business phone system?

A business phone system routes calls between your staff and the outside world and adds features consumer lines lack: extensions, auto attendants, call queues, ring groups, recording and reporting. Many are now delivered as cloud software rather than hardware on site.

How much should a business phone system cost per user?

It depends on what each plan includes, so compare quotes on the same basis: minutes, numbers, recording, analytics and contact-center features. For reference, OttoCall's Standard plan is $34.99 per user per month; see the pricing page for what it includes.

Cloud or on-premise — which is better?

Cloud avoids upfront hardware and maintenance contracts and suits teams that work from several places. On-premise can still make sense where rules require calls to stay on site or a site has no reliable internet. Compare both on your own requirements.

How long does it take to switch phone systems?

It depends on how many numbers you port, how many sites and call flows you have, and how much testing you need. Porting timing depends on the number and your current provider. The VoIP migration checklist at /guides/voip-migration-checklist lists the steps to plan.

Will we lose calls when we switch?

Reduce the risk by staging the cutover: set up the new service in parallel, move numbers in batches and keep the old service until the new one is proven.

Buyer's guide

How to choose a business phone system

A vendor-neutral framework for comparing phone systems — plus the questions buyers often forget to ask until after they've signed.

Written and reviewed by OttoCall Editorial Team · Last reviewed 10 November 2026

1. Decide cloud, on-premise or hybrid

Cloud: no PBX hardware, a monthly per-user fee, updates included
On-premise: upfront hardware, a maintenance contract and periodic refreshes
Hybrid: keep a recent PBX and move the lines to SIP trunks (see /sip-trunking)
Compare all three on your own quotes over the same period

2. Size the real cost

Per-user licence × seats × contract length
Number rental and porting fees
International and toll-free minutes
Add-ons: recording, analytics, contact center, single sign-on
Handsets and headsets
Internal admin time

3. Features to insist on

Auto attendant and menus you can edit yourself
Time-based and skill-based routing
Call recording with retention controls
A mobile app with presence
Reporting on queues and missed calls
A clear answer on which of your tools can connect

4. Ask about reliability

Is an uptime SLA published, with service credits?
How are calls routed if a carrier or your office internet fails?
Is there a public status page?
What are the support response targets by severity?
Who do you escalate to?

5. Plan the migration

Audit every number first
Document existing call flows before changing them
Pilot with one team
Port numbers in batches
Keep the old service until the new one is proven

6. Vendor checklist

Published pricing
A free trial
Number porting costs
Numbers available in every market you sell in
API and webhook options
Support hours on your plan

Ready to compare a provider?

See how OttoCall answers these questions

The VoIP phone service page covers what OttoCall's plans include and how to start; Cloud Phone lists the extensions, routing, voicemail and admin features.

OttoCall VoIP phone service Cloud Phone features

Frequently asked questions

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