How to Forward Calls to an Answering Service: Step by Step

How to Forward Calls to an Answering Service: Step by Step

Picture a one-truck plumber at 9:15 on a Sunday night. He has just signed up for an answering service, and the plan is simple: his cell rings first, and the service catches only the calls he misses while he is flat on his back under a sink. He searches for how to forward calls to an answering service, grabs the first code he finds, and dials it. The screen says forwarding is on. He goes to bed pleased with himself.

Twenty-five minutes later his wife calls from her sister's house to say goodnight. His phone never rings. She hears a polite greeting asking how the company can help with a plumbing problem. A moment later a text summary of her goodnight call buzzes on his phone, and he stares at it. The code he found forwards every call, not just the ones he misses, and she has just become the answering service's first caller.

This guide fixes that. You will see which kind of forwarding to use, the exact codes for the major carriers, where to find the settings on iPhone, Android and business phone systems, and how to test it before a real customer calls. We will come back to the plumber in the middle and at the end.

How to forward calls to an answering service: the short answer

You forward calls to an answering service by telling your phone carrier (or your phone system) to send calls to the service's phone number. There are two choices that matter:

The mechanics are the same either way: get the number your service gave you, dial the carrier's code or flip the setting, then test it from another phone. Codes and charges vary by carrier, so confirm the details with yours. The same steps work if you are learning how to forward calls to another number for any reason. For the plain-English definition, see our glossary entry on call forwarding, or see how Callbook handles a forwarded call from ring to booked job.

Unconditional vs conditional call forwarding

Forward all calls (unconditional)

Unconditional forwarding sends every incoming call to the other number, no matter what your phone is doing. It stays on until you cancel it, which is both its strength and its trap. It is great when you truly want the service to take everything, like a week off. It is a bad fit if you only want help during busy stretches, because customers who would have reached you now reach the service first.

Conditional call forwarding: no answer, busy, unreachable

Conditional call forwarding has three triggers, and many carriers let you set each one separately:

A sensible setup for a small business is to turn on all three, so the only time a caller meets voicemail is when the service itself cannot pick up. That is how you forward unanswered calls without losing the ones that never ring at all.

Simultaneous ring, a third option

Some setups ring your phone and the service at the same moment, and whoever picks up first gets the call. That is not a carrier code, it is a feature of a phone system or a service. Callbook supports it, and so do many VoIP systems. Our glossary page on simultaneous ring explains when it helps.

Before you start

Most forwarding failures are not technical. Get the exact number from your service and read it back, because one wrong digit sends customers to a stranger. Forward the line customers actually dial: if you advertise a landline, a VoIP number or a second number on a truck decal, forwarding your cell does nothing for those calls. Decide whether you want all calls, only missed calls, or only after hours before you pick a code. And keep a second phone nearby, since you cannot test forwarding by calling yourself.

Forwarding codes by carrier

Dial the code on your keypad, then press Call, and wait for a confirmation tone or message. In the table, 5551234567 stands in for the 10-digit number your answering service gave you. These are the common codes, but confirm them with your carrier because codes and charges vary.

A few notes on reading the table. AT&T and T-Mobile use GSM-style codes: a code, the 10-digit number, then a pound sign. The Verizon codes are the star code immediately followed by the number, with no extra symbols. Landlines and cable or VoIP home lines follow the star-code pattern in most cases, but conditional forwarding on those lines varies and is often a setting in the provider's online portal. A good business phone system makes that a few clicks.

How to forward calls on an iPhone or Android phone

You do not have to dial codes if your phone offers a menu for it.

iPhone. Go to Settings, then Phone (in newer versions of iOS the path is Settings, then Apps, then Phone), then Call Forwarding. This works on carriers that support it, which generally means AT&T and T-Mobile. Verizon customers use the dial codes above. Look at which options your carrier exposes there, because the menu may not offer every conditional rule.

Android. Open the Phone app, then Settings, then Calls or Supplementary services, then Call forwarding. Menu names vary by phone maker and carrier, so if your phone calls it something else, search the settings for "forwarding."

Whichever route you take, finish with a real test call. A switch that looks on in a menu does not prove the call actually lands.

Business VoIP admin apps

If your business number lives in RingCentral, Nextiva, Dialpad or Grasshopper, forwarding is a rule in the admin app, not a dial code. You add the answering service's number as a destination, then choose when it applies. Setting names differ by product, so use the vendor's help pages.

After-hours forwarding

Many owners want the service only at night. On a cell phone, you can set forward-all at closing time and cancel it in the morning, but that relies on you remembering. A business phone system usually lets you set hours so calls ring your team by day and the service after. If you are weighing whether nights and weekends alone are worth covering, our page on after-hours answering service lays out the options.

How to test your forwarding

A rule is not finished until you have called it from the outside. Use a second phone, and a different carrier if you can.

Common mistakes

Call forwarding answering service setups: what the service does next

Forwarding only moves a call. What happens next depends on what is on the other end: a person taking a message, an AI receptionist that can book the job and text you the details, or plain voicemail. If you are not sure you need one, do I need an answering service walks through the decision, and how an answering service works explains what happens after the call is forwarded.

Callbook is one option. You keep your existing business number and forward calls to your Callbook number: all calls, only the ones you do not answer (no answer or busy), or only after hours. It answers in a natural-sounding voice, in English and Spanish, uses your own scripts and prices, and books on your Google Calendar. If someone needs a person, it transfers the call to the number you choose for transfers, or to a separate emergency number for gas, fire, carbon monoxide or electrical shock, and texts whoever picks up the reason. Otherwise it takes a voicemail or a callback request, and you get a text summary after each call.

It has limits. Transfers go to one forwarding number, not to different people by department. It leaves a flat buffer after each job but does not calculate drive time between jobs. And a live human service is still the right fit for some businesses. For a one-truck plumbing shop, answering, booking from a calendar and texting a summary may be all you need.

A worked example (illustrative numbers)

Say the plumber chose Callbook's Starter plan, which is $79 base with 250 minutes included and $0.40 per minute over that. Scenario (illustrative numbers): his line takes about 140 calls in a month, averaging 2.5 minutes each.

The base price is the same every month; minutes past the included amount cost $0.40 each. These numbers are made up, and your volume will differ. The point is that forward-all sends the service calls you would have answered yourself, and those minutes count. See current plans on the pricing page.

Example: fixing a forward-all mistake with *71

Here is how the plumber fixes his setup, still on that Sunday, after his wife's call lands on the greeting. He is on Verizon, so he uses the star codes.

1. He dials *73 and presses Call to cancel the forward-all he set earlier, and waits for the confirmation.

2. He dials *71 followed by the answering service's number and presses Call, so only calls he does not answer or that find him busy will move over.

3. He asks his wife to call again from her sister's house. This time his phone rings, and he answers it. Goodnight, delivered.

4. He asks her to call a third time and lets it ring. The answering service picks up, and a text summary arrives on his phone a moment later.

5. He stays on a call with his wife while her sister dials his number from another phone. That call finds him busy, moves to the service, and another text arrives.

By 10:30 he has tested answered, unanswered and busy. One gap remains: *71 is documented for unanswered and busy calls only, so he will ask Verizon how a switched-off phone is handled.

Call forwarding setup checklist

1. Get the exact forwarding number from your answering service and read it back.

2. Decide: forward all, forward only missed calls, or after hours only.

3. Dial the right code for your carrier, or set the rule in your phone menu or VoIP admin app.

4. Call from a second phone and test answered, unanswered and busy.

5. Check that your own voicemail is not answering first.

6. Ask your carrier about airtime charges and ring time.

7. Write down the cancel code (*73 on Verizon, ##002# on AT&T and T-Mobile).

8. Set a reminder to review it after the first week.

At 11:20 the next morning the plumber is under a bathroom sink with a wrench in one hand and a flashlight in his teeth when his phone rings. He cannot answer it. It rings on, the call moves to the answering service, and a few minutes later a text summary tells him what the caller needed. His wife calls at noon. The phone rings, and he picks up. Both calls went where he wanted them to.

Try Callbook free - forward your missed calls and see what gets booked.

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