How to forward calls to an AI receptionist or answering service (2026)

You keep your business number and set your carrier to forward calls to the AI’s number, either every call or only the ones you don’t pick up. On Verizon, dial *71 plus the AI number to forward missed and busy calls, or *72 for all calls (*73 turns it off). On T-Mobile, dial **61*1 plus the number and # for unanswered calls, or **21*1 plus the number and # for all calls. On AT&T wireless, set it in your phone’s call-forwarding settings.

The codes are different on every carrier, and using another carrier’s code simply does nothing. Below are the codes from each carrier’s own support pages (checked October 2026), which setup to choose, and a two-minute test so you know it works before you rely on it.

Which forwarding setup should you use?

There are three, and most service businesses want the first.

Carriers don’t schedule forwarding for you. For “after hours only,” you either turn all-calls forwarding on at close and off when you open, or leave it on all the time and let the AI handle after-hours calls differently, which many AI receptionists support.

Verizon call forwarding codes

From Verizon’s call forwarding guide (last reviewed by Verizon in 2023; the codes were still current when we checked in October 2026):

With *71, Verizon says your phone rings “three or four rings” before the call forwards, so you still get a chance to answer. Verizon also notes that “airtime charges still apply to all forwarded calls,” so check your plan if you’re on a limited-minutes plan. You can’t forward to an international number.

T-Mobile call forwarding codes

T-Mobile lists these on its short codes page. Put a 1 before the 10-digit number.

T-Mobile also lets you change how long the phone rings before forwarding: **61*1 + number + ** + seconds + #, using 5, 10, 15, 20, 25 or 30 seconds. If you want a chance to answer, 15 or 20 seconds is a reasonable starting point.

For “missed calls only,” set unanswered and busy. Add unreachable (**62) if you also want calls to reach the AI when your phone is off or has no signal.

AT&T call forwarding

AT&T wireless (mobile): AT&T’s device support guide sets forwarding in the phone itself. On the Android phone it documents, that’s the Phone app → Settings → Calling accounts → your SIM → Call forwarding, with options for always, when busy, when unanswered and when unreachable. Menus vary by phone.

AT&T home phone (landline): AT&T’s home phone guide uses *72 plus the number to forward all calls and *73 to turn it off. For “busy” or “don’t answer” forwarding on a landline, AT&T says to call 800.288.2020 for help.

What about iPhone?

On an iPhone, the Call Forwarding switch (Settings → Apps → Phone → Call Forwarding) sends all calls to the number you enter. Apple’s guide says that for conditional forwarding, when you’re busy or out of service, you need to contact your carrier. So on Verizon or T-Mobile, iPhone owners who want “missed calls only” should dial the carrier codes above from the iPhone’s keypad. On AT&T, which doesn’t list wireless codes, ask AT&T to set up conditional forwarding, or use the all-calls switch.

What about VoIP and office phone systems?

Business VoIP services (RingCentral, Google Voice, Grasshopper, desk-phone systems) don’t use star codes. Look in the provider’s app or admin settings for “call forwarding,” “call handling” or “unanswered calls,” and point the no-answer rule at the AI’s number. The same three setups apply.

How do you test call forwarding?

Do this once after setup, and again any time you change carriers or phones. Busy forwarding is hard to test yourself: with call waiting on, a second call just rings through and then follows the no-answer rule, so the unanswered test covers most cases.

1. Call your business number from a different phone. Don’t call from the phone that’s forwarding.
2. Let it ring without answering. With “missed calls only,” it rings for your carrier’s delay (three or four rings on Verizon, or the seconds you set on T-Mobile), then the AI should pick up.
3. If you set the unreachable rule (T-Mobile **62, or AT&T’s “when unreachable”), turn your phone off and call once more. Verizon’s *71 covers busy and unanswered calls only, so skip this step on Verizon.
4. Check where the call landed. With an AI receptionist you should see the call, recap or transcript in its log within a minute or two.

If it goes to your carrier voicemail instead of the AI, the conditional forwarding didn’t take. The usual cause is a mistyped number, a missing 1 on T-Mobile, or the wrong carrier’s codes.

Common forwarding problems

• Calls go to voicemail, not the AI. Your carrier voicemail is answering first. Conditional forwarding replaces voicemail for those calls, so re-enter the code and test again.
• Callers hear a busy signal. Verizon’s guide says to check the forwarding number for a stray extra digit.
• It worked, then stopped. If you changed phones, plans or carriers, check the forwarding status and re-dial the code.
• You forwarded to the wrong place. On T-Mobile, ##004# resets forwarding to the default. On Verizon, *73 turns it off.

A worked example: a two-truck HVAC shop

The owner is on T-Mobile and wants to answer when he can, with the AI catching the rest. He dials **61*1 + the AI number + **20#, which forwards unanswered calls after 20 seconds, then **67*1 + the number + # for calls that arrive while he’s busy, and **62*1 + the number + # for when his phone is off. He calls from his partner’s phone to test: it rings for about 20 seconds, then the receptionist answers. From then on, calls he can’t take go to the receptionist, within his plan’s minutes.

If he later wants every call handled for a week, he dials **21*1 + the number + #, and ##21# when he’s back. For what his shop should text the callers who still slip through on a heat-wave day, see missed-call text-back for HVAC.

How this works with Stack Space

Every Stack Space plan includes a phone number for the AI receptionist, so you keep your existing business number and forward to it using the codes above. Once your AI number is set up, the app shows the forwarding codes for your carrier with that number filled in. The receptionist answers 24/7 within your plan’s minutes, books onto your calendar and sends you a summary of each call. Plans start at $30/mo (45 minutes) and Starter is $125/mo with 250 minutes. If you only forward missed calls, minutes go further, because you’re still answering the rest yourself.

If you’re still deciding whether an AI or a person should answer, see AI answering service vs a human answering service and what an AI receptionist costs. For what happens on the calls themselves, see what happens when AI answers your calls.

FAQ

What is the code to forward calls on Verizon?

*72 plus the 10-digit number forwards all calls, *71 plus the number forwards only busy and unanswered calls, and *73 turns forwarding off (Verizon support, checked October 2026).

What is the T-Mobile code for conditional call forwarding?

**61*1 plus the 10-digit number plus # forwards unanswered calls. Add **67*1…# for busy and **62*1…# for unreachable. ##004# resets forwarding to T-Mobile’s default.

Does AT&T have a call forwarding code for cell phones?

AT&T’s support pages set wireless forwarding in the phone’s settings (Call forwarding → when busy, unanswered or unreachable) rather than publishing dial codes. AT&T home phones use *72 and *73.

Can I forward calls to an answering service and keep my number?

Yes. Forwarding happens at your carrier, so customers keep calling the number on your truck and website. You can turn it off at any time with the carrier’s off code.

Do forwarded calls cost extra?

It depends on your plan. Verizon says airtime charges apply to forwarded calls. On unlimited plans that usually doesn’t matter, but check if you’re on a limited-minutes plan.