How to Set Up a Phone System for a New Office (Step by Step)

Jump to:

• Before You Start: Questions to Answer
• Choosing the Right System Type
• Getting Your Business Phone Number
• Internet Requirements for VoIP
• Phone Hardware: What to Buy
• Installation Day: What to Expect
• Your First Week: Configuration Checklist
• Frequently Asked Questions

Before You Start: Questions to Answer

Before you talk to a single phone vendor, answer these five questions. They’ll determine what type of system you need and how much you should budget.

How many people need phones? Count every person who makes or receives business calls. Include the reception desk, conference rooms, and common areas like a break room or warehouse floor. Don’t forget: some people may need a desk phone and a mobile app.

Do you need a local number, toll-free number, or both? Most small businesses start with a local number. If you serve customers nationally, a toll-free number adds credibility. You can always add numbers later.

Do you need a receptionist menu (auto attendant)? If callers need to reach specific people or departments, yes. If every call goes to the same person, probably not yet. See our auto attendant setup guide when you’re ready.

How important is uptime? If missing phone calls for an hour costs you real money (medical offices, service businesses, sales teams), you need a system with failover protection. If you can survive a brief outage by checking voicemail from your cell, a simpler system works.

What’s your budget? Phone systems range from free (Google Voice on your cell phone) to significant (on-premises hardware with enterprise features). Most small offices spend $200 to $600 per phone for hardware plus $20 to $40 per user per month for service. On-premises systems have higher upfront cost but lower ongoing monthly fees.

Choosing the Right System Type

Cloud VoIP (Best for remote/hybrid teams)

Everything runs in the cloud. You plug phones into your internet and they connect to the provider’s servers. No equipment in your office beyond the phones themselves. Setup takes hours, not days. Monthly cost per user. Easy to add or remove users. The downside: your phone system is only as reliable as your internet connection.

On-Premises VoIP PBX (Best for offices that need reliability)

A phone server sits in your office and handles all call processing locally. Phones connect to this server over your local network. Outside calls use SIP trunks over your internet connection, but internal calls, paging, and intercom work even during internet outages. Higher upfront investment, but you own the equipment and monthly costs are typically lower. Phonewire installs these systems in a single day.

Hybrid (Best of both worlds)

On-premises hardware for reliability, cloud features for flexibility. Your office phones run locally. Your remote workers use the cloud app. Both connect to the same system. This is what most growing businesses end up wanting.

What About Just Using Cell Phones?

Cell phones work fine when you’re a one-person operation. They stop working well when you have three or more people, when customers need to reach “the office” rather than a specific person, when you need to transfer calls between employees, or when you want a professional auto attendant greeting. If you’re at that stage, you need a real phone system.

Getting Your Business Phone Number

New number: Your phone provider can assign a local or toll-free number instantly. Pick an area code that matches where your customers are. The number is ready to use the day your system is installed.

Porting an existing number: If you already have a business number (on a cell phone, landline, or previous provider), you can transfer it to your new system. This is called number porting. It takes 5 to 15 business days, and during that time your old phone still works. The cutover happens in minutes once the port completes.

Vanity numbers: Numbers like 1-800-YOUR-BIZ are available through most providers for a small premium. They’re easier for customers to remember, especially if you advertise on radio, TV, or billboards.

Multiple numbers: You can have several phone numbers all ringing into the same system. A local number for local customers, a toll-free number for national reach, and a separate number for your fax or dedicated line. They all route through one phone system.

Internet Requirements for VoIP

VoIP calls use about 100 Kbps of bandwidth per active call. Ten simultaneous calls need about 1 Mbps. Most modern business internet plans provide 100 Mbps or more, so bandwidth itself is rarely the bottleneck.

What matters more is quality and consistency. VoIP is sensitive to packet loss, jitter, and latency. A connection that downloads files quickly but has intermittent drops will produce choppy, robotic-sounding calls.

Minimum recommendation: 25 Mbps download / 10 Mbps upload with less than 30ms latency and less than 1% packet loss. Fiber or cable internet. Avoid satellite and fixed wireless if VoIP is mission-critical.

Best practice: Use a separate VLAN (Virtual LAN) for your phones so voice traffic gets priority over regular internet browsing and downloads. Most managed network switches support this, and your phone installer should configure it during setup.

Phone Hardware: What to Buy

Reception desk: A phone with a large display, multiple line buttons, a sidecar module for one-touch dialing, and a headset port. The receptionist handles the most calls and needs the most capable phone.

Standard desks: A mid-range phone with 4 to 6 line buttons, speakerphone, and a clear display. This covers most employees. Models from Yealink, Polycom, and Cisco are all reliable choices.

Conference rooms: A conference phone (the triangular speakerphone) with good microphone pickup for groups of 4 to 10 people. For larger rooms, add extension microphones.

Warehouse/shop floor: Rugged cordless phones that can handle dust, drops, and noise. Standard desk phones won’t survive a warehouse environment.

Headsets: For anyone who spends more than 2 hours a day on the phone, a wireless headset is worth the investment. It frees their hands and lets them move around while talking. See our guide on best business Bluetooth headsets.

Installation Day: What to Expect

With professional installation, here’s what a typical day looks like:

Morning: The installation team arrives with all equipment pre-configured. They install the phone server (if on-premises), run any necessary cabling, and place phones on desks. If you have an existing network switch that supports VoIP, they’ll configure it. If you need a new switch, they bring one.

Midday: Programming begins. Extensions get assigned, ring groups configured, auto attendant recorded, voicemail boxes created, and call routing set up according to the call flow you planned in advance.

Afternoon: Testing. Every phone gets tested for incoming calls, outgoing calls, transfers, hold, intercom, paging, and voicemail. The number port is initiated (or completed if it was started beforehand). Your team gets hands-on training with the phones.

End of day: Everything is operational. You make a test call from your cell phone to the new number and verify it rings the right phone. The installation team leaves their direct support number for any questions that come up in the first few days.

That’s a Phonewire installation. Other providers may spread this over multiple days or ship equipment for you to self-install. If you’re comfortable with technology, self-install can work for cloud systems. For on-premises systems, professional installation is strongly recommended.

Your First Week: Configuration Checklist

Even after professional installation, there are things to dial in during your first week of use.

Record your voicemail greetings. The installer may set up default greetings, but each person should record a personal greeting. “Hi, you’ve reached [name] at [company]. I’m away from my desk…”

Test your auto attendant from an outside line. Call your number from a cell phone and walk through every menu option. Does the hold music sound right? Does the after-hours greeting play at the right time?

Set up voicemail-to-email. Make sure voicemails land in your inbox so you don’t have to check a physical phone for messages.

Configure mobile apps. If your system includes a mobile app, install it on your phone. This lets you make and receive calls on your business number from anywhere. Test it on Wi-Fi and cellular.

Update your marketing materials. Google Business Profile, website, business cards, email signatures. Every place your phone number appears should reflect the new number (or confirm the ported number is working).

Set up a contact in your phone for your own office number. This sounds trivial, but you’ll call your own office regularly to test things, check voicemail, and demonstrate the system to others. Make it easy.