How to Forward Business Calls to an Answering Service: Setup Guide

How Call Forwarding Works with a Modern Answering Service

One of the most common misconceptions among small business owners is that using an answering service requires getting a new phone number. You do not need to change your number.

Your business phone number—whether advertised on Google Business Profile, printed on vehicle wraps, or stored in customer address books—stays exactly where it is. When an answering service like KaiCalls provisions your account, you receive a private, dedicated routing number. You then tell your existing phone carrier or virtual phone system when to forward calls to that number.

Modern telecommunication networks preserve the original caller's information. When a prospect calls your primary business number and your line forwards to the answering system, the answering service still sees the caller's actual phone number via Carrier Caller ID Pass-Through, ensuring full attribution and accurate callback logs.

The 3 Forwarding Modes: Which Fits Your Business?

Depending on how you run your daily operations, you can choose from three standard forwarding architectures:

Mobile Carrier Star Codes Reference Guide

On most US mobile carriers, conditional and unconditional forwarding can be enabled directly from your phone's dial pad in seconds:

Setting Up Forwarding in Virtual Phone Systems (VoIP)

If your small business uses a cloud VoIP provider, forwarding is typically managed through your web dashboard:

1. Google Voice for Business

Log in to your Google Voice dashboard, open Settings (gear icon), scroll to Calls, and select Forward calls to linked numbers. Enter your dedicated answering service routing number. If you only want after-hours coverage, use Google Voice's Working Hours feature to toggle forwarding automatically.

2. RingCentral

Navigate to Settings > Call Handling & Forwarding. Under your User or Main Company Line, configure your ring sequence. You can set incoming calls to ring your mobile app for 15 seconds, and then forward to your external answering service number if unanswered.

3. Grasshopper

Open Settings > Extensions. Select your main extension, click Forwarding Numbers, and add your answering number. Ensure you set the call handling order to "Ring my primary phone first, then roll over to answering service" or set it as the primary destination outside business hours.

4. Nextiva

In the Nextiva Voice portal, navigate to Users > Call Routing. Choose Call Forwarding Selective or Call Forwarding When Busy / No Answer and input your KaiCalls forwarding number.

5 Essential Pre-Launch Testing Rules

Follow these 5 rules before making your answering service live for actual customers:

1. Never Test by Calling Yourself: If you dial your business line from the exact same phone, most carriers bypass forwarding and connect you directly to your voicemail management menu. Always test by having a colleague or friend call your business number from an external phone.
2. Verify Caller ID Pass-Through: When the test call comes through to the answering service, confirm that the caller's real phone number is captured in the intake log rather than your own office number.
3. Check Carrier Voicemail Timing: If you use conditional forwarding (*71 or *61), ensure your carrier's default ring duration (usually 20–25 seconds) gives callers enough time to ring through to the answering service before your cell carrier's personal voicemail kicks in.
4. Perform a Busy-Line Test: Place an active outbound call from your mobile phone, and have a third party dial your business line simultaneously. Confirm that the incoming call seamlessly forwards to your answering service instead of issuing a busy tone.
5. Save Activation & Deactivation Shortcuts: Store the star codes in your phone contacts (e.g. "Forward ON" = *72-555-0100 and "Forward OFF" = *73) so you can toggle forwarding with a single tap from your steering wheel or job site.