"How much does a business phone system cost?" has no single answer, because "phone system" covers very different things: a second number on your cell, a cloud phone service priced per user, a PBX box in a closet with desk phones on every desk, an answering service, or an AI that answers for you. Each one is priced differently, and the cheapest monthly price is often not the cheapest system over three years.
This guide breaks the cost into upfront and monthly pieces for each option, gives published prices from named vendors with the date we checked them, and ends with a three-year worksheet you can use to compare quotes. For the VoIP service bill on its own, see how much VoIP costs.
Upfront costs vs monthly costs
| Cost | Upfront | Monthly or per use |
|---|---|---|
| Service plan | Per user, per line or per number | |
| Phone numbers | Porting or activation fees on some plans | Extra numbers, toll-free minutes |
| Hardware | Desk phones, conference phones, headsets, adapters | Leasing, if you lease |
| On-site PBX | The system, licenses, installation | Maintenance contract, SIP trunks or phone lines |
| Network | Switches, cabling, battery backup | Business internet, a backup connection |
| Answering | Staff time, an answering service or AI, priced per call, minute or credit | |
| Taxes and fees | Federal, state and local fees on your service |
Option 1: a cell phone with a business number
The lowest-cost start. You keep your phone and add a separate business number through an app. Google Voice's individual Starter plan is $10 a month, and its team plans are $10, $20 or $30 per user a month with a Google Workspace plan billed separately (Google Voice pricing, checked October 19, 2026). Grasshopper's plans start at $14 a month billed annually (from our Grasshopper comparison, checked October 18, 2026).
Upfront cost: none. The hidden cost: every call depends on you picking up, and the number is hard to share as you hire.
Option 2: a cloud phone system (hosted PBX)
The usual choice for teams with people at desks. You pay per user per month and get extensions, a phone menu, ring groups and voicemail, managed online. Published examples, billed annually: Zoom Phone from $16 per user (Zoom Phone pricing), Ooma Office from $19.95 per user with no contract (Ooma Office plans), Dialpad Connect from $15 per user (Dialpad pricing), all checked October 19, 2026, and RingCentral RingEX from $20 per user for 1–5 users (our RingCentral comparison, checked October 18, 2026). Our hosted PBX guide explains what you get for that.
Upfront cost: devices if you want them, plus any activation fee. Ooma lists a one-time $29.95 activation fee at sign-up (checked October 19, 2026).
Option 3: an on-site PBX
A phone system you own, installed in your building by a dealer, connected to the outside world through SIP trunks or phone lines. Pricing comes as a custom quote: the system itself, licenses per phone, installation and programming, cabling, a maintenance contract and the monthly trunk or line charges. It can make sense for large sites with existing cabling and in-house IT. For most small businesses, the hardware refresh cycle and maintenance contract make cloud service simpler.
Ask the dealer to price five years: the box, licenses, installation, maintenance, trunks and the cost of replacing phones when they reach end of support.
Option 4: traditional business lines
Copper lines from the local phone company, priced per line by quote. They are being retired: in March 2026 the FCC adopted an order that eases the rules for carriers retiring copper and discontinuing legacy voice service (FCC 26-19, checked October 19, 2026). If you still have copper lines, read POTS lines and copper retirement before you sign a new term.
Hardware: what devices cost
If you want desk phones, here are published prices from one provider's phone store (Ooma's phone store, checked October 19, 2026), as examples of the range:
| Device | Listed price |
|---|---|
| Grandstream GRP2613 IP phone | $99.99 |
| Grandstream GRP2624 IP phone | $129.99 |
| Yealink T48U IP phone (touchscreen) | $299.99 |
| Yealink CP920 conference phone | $399.99 |
| Grandstream HT812 adapter (connects two analog phones or a fax) | $69.99 |
Most teams don't need a desk phone for everyone. A headset and the provider's app cover most roles. Buy desk phones for reception, shared rooms and anyone who is on the phone all day.
The cost of answering
Every phone system above rings someone. If nobody is free, the call goes to voicemail. That is the biggest cost most quotes leave out, and there are three ways to cover it:
- Your own staff: The cost is their time, and the calls they miss while they do other work.
- An answering service: Live operators answer from your script. As an example, Smith.ai lists human receptionist plans from $300 a month for 30 calls and an AI receptionist from $150 a month for 75 calls (our Smith.ai comparison, checked October 18, 2026).
- An AI receptionist or add-on: Some phone systems sell AI answering on top: RingCentral lists its AI Receptionist from $39, and Quo sells AI calls in credit tiers from $0 to $199 a month (Quo pricing; RingCentral from its pricing page; both checked October 19, 2026).
Our guide to AI receptionists vs answering services vs voicemail compares these in depth, and the missed call cost calculator puts a number on unanswered calls using your own figures.
A three-year worksheet
Fill this in for each quote. Three years is long enough to include hardware and short enough to be realistic about prices.
- Users × monthly price per user × 36.
- + extra numbers × monthly fee × 36.
- + add-ons you need (queues, recording, analytics, AI) × 36.
- + texting registration (one-time fee + monthly fee × 36).
- + devices and adapters (one-time).
- + activation, setup, porting and installation (one-time).
- + estimated taxes and fees × 36 (ask for an estimate at your address).
- + answering cost: staff hours, a service or AI, × 36.
- = three-year total. Divide by 36 for a true monthly cost.
Questions to ask every vendor
- What is the price at our user count on monthly and annual billing?
- Which features we listed are included, and which are add-ons?
- What taxes and fees should we expect at our address?
- What is the contract term, and what does it cost to leave early?
- Can we port our current numbers in, and out again later, and is there a fee?
- What happens to calls during an internet or power outage?
How Chargezen helps
Chargezen covers the answering part of the bill, not the phone hardware. Concierge answers every call and text on your business number, and your team joins from their phones or the browser when a customer needs a person.
- One US number for calls and texts: Get a toll-free or local US number in Chargezen, search open numbers by area code on phone numbers, or bring the number you already have. Chargezen files the carrier registration texting needs. See a business phone number.
- Concierge answers every call and text: Day and night, with the opening line you write, answering from the information you give it. It recognizes returning callers by their number. See the AI receptionist and the phone channel.
- Teammates join from Finn or the browser: When a customer needs a person, Concierge alerts your team in the Finn app and the browser, and emails or texts the teammates you pick. Listen in with your microphone off, tap Join the call, and Concierge tells the caller you're there. From the Finn app on iPhone or Mac you can transfer the call to a teammate, with a note. See phone calls.
- Calls and texts out from the business number: Teammates call and text customers from Finn, and the customer sees the business number, not a personal cell. See why that matters.
- Recording by your rules: Set each number to always record or never record. Callers hear your notice before recording starts, and you choose how long recordings are kept. See call recording.
To be plain about what Chargezen is not: it doesn't sell VoIP lines, desk phones or a PBX. It has no extensions, phone menu, ring groups, call forwarding, simultaneous ring or business-hours routing, and it offers US (+1) numbers only. If you need those, buy a phone system built for them. Chargezen answers the calls and texts on your business number, and your team works the same conversations from there.
Concierge Starter is $20 a month with 20,000 credits. Pro is $199 a month with 199,000 credits, or $1,990 a year. Phone and text charges are billed as used, with no per-user fees. See pricing.
Related terms: AI receptionist, AI answering service, IVR and number porting. Related guides: how much VoIP costs, hosted PBX explained and a phone system buyer's guide for plumbers. See also how VoIP works and small business phone plans.
Frequently asked questions
What does a small business phone system cost per month?
Published cloud plans start around $15 to $20 per user per month billed annually (see the examples above, checked October 19, 2026), before taxes, fees, add-ons and devices. Use the worksheet to get your real figure.
Should I buy or lease desk phones?
Buying is usually cheaper over three years if you need only a few. Leasing can make sense for a large rollout where the vendor replaces broken phones. Many teams need fewer desk phones than they think.
Is an on-site PBX cheaper in the long run?
Sometimes, for large sites with in-house IT. For most small businesses, maintenance, upgrades and trunk charges close the gap. Price five years of both before deciding.
Can I mix options?
Yes. Many businesses keep a cloud phone system for the office and add an answering service or AI agent for after hours and busy periods.
