Best for: Small offices with low-to-moderate call volume, owner-operated businesses.

The simplest failover setup: if your internet circuit goes down, your main business number automatically forwards to a designated cell phone. The owner, manager, or a senior employee receives inbound calls on their mobile as if they were at the office. Phonewire configures the routing rule at the system level — you don’t do anything when the outage happens. It detects the failure and reroutes automatically.

A step up from basic forwarding: more robust setups map individual extensions to employee cell phones. A customer dials your number, punches in extension 105, and that call forwards to that employee’s cell even if the office internet is completely down. Outbound calls from that cell can still display your business number on caller ID — the customer sees your business name, not a personal number.

The honest limitation: Works well when one or two people can handle most inbound calls. Gets complicated with high call volume, a staffed reception desk, or departments that need to be reached separately. Also depends on employees being willing to take business calls on personal devices — which can create pushback if those are personal phones.

Best for: Businesses already using an auto-attendant, multi-department offices.

When the internet fails, calls route to a cloud-hosted auto-attendant rather than directly to a single cell phone. The caller hears your normal greeting and menu options — “Press 1 for Sales, Press 2 for Service” — and the system routes each selection to the appropriate employee’s cell phone. From the caller’s perspective, nothing unusual happened.

Voicemail still works during an outage because it lives in the cloud data center, not on your local hardware. Voicemails are emailed to employees immediately so they can listen and respond from anywhere, on any device.

The honest limitation: Requires that staff have mobile devices capable of receiving business calls. If employees use personal cell phones and push back on taking business calls on personal devices, this creates friction. If your business provides mobile devices to staff, it’s a non-issue — you call the shots on what those devices are used for.

Best for: Offices in areas with two available ISPs, businesses that can’t afford any phone disruption.

Your office has two separate internet connections from two different providers — say, AT&T and Spectrum. The phone system’s router monitors both circuits constantly. When one fails, traffic automatically shifts to the other. Your desk phones keep ringing. Your staff doesn’t notice. Your customers don’t notice.

Phonewire includes a dual-WAN router in proposals where this approach makes sense and configures the failover logic before installation day. Everything is automatic when an outage happens — no manual switching, no IT intervention required.

The honest limitation: You need two genuinely independent providers — two circuits from the same provider don’t protect against a provider-wide outage. In many suburban and rural markets, there is only one viable high-speed business ISP, which makes this option unavailable. It also requires static IP addresses on both circuits, which Phonewire handles during installation.

Best for: Most small businesses. The cleanest solution available.

This is the option that didn’t exist when most of the “VoIP goes down with the internet” horror stories were written — and it’s now Phonewire’s primary recommendation for businesses that want a phone system they never have to think about.

The Phonewire Hybrid system has a cellular failover module built directly into the hardware. When your internet circuit fails — for any reason, from any provider — the system detects the outage within seconds and automatically routes calls over the cellular network. Your desk phones keep ringing. No configuration change. No forwarding to a personal cell. No auto-attendant workaround. The same phones, the same extensions, the same experience for your staff and your callers.

When your internet comes back, the system switches back automatically. Most internet outages at small businesses last under two hours. Your customers will never know it happened.

The honest limitation: There is on-premises hardware — installed at your location by Phonewire. It’s not a cloud-only app. If you want phones that work with no compromises during an outage, it’s the right answer for most businesses with 10 or more employees.