Call forwarding basics

If you've never set up call forwarding before, or if you've done it a thousand times but got confused by something, this is the plain-English explainer.

What is call forwarding?

Call forwarding is a feature built into almost every phone service — wireless carriers, landlines, and business VoIP systems. When enabled, calls to your number ring somewhere else instead. You can use it to route calls to a colleague, your cell, a call center, an answering service, or an AI receptionist like Human Add AI.

The thing that forwards is your number, not your device. Callers still see your business number. They never know the call was routed — it just rings somewhere else.

Unconditional vs. conditional forwarding

There are two major flavors:

Unconditional forwarding ("Forward Always")

Every call, no matter what, routes to the destination. Your own phone never rings. Most common star code: *72 to enable, *73 to disable. On GSM carriers (AT&T, T-Mobile) it's often **21*NUMBER#.

Use unconditional when: you're out of the office, you want an AI to handle every call, or you're on vacation.

Conditional forwarding

Calls only forward in specific situations. Three sub-types:

On busy — forward when your line is already on a call. Code varies (often **67* or *90).
On no-answer — forward after the line rings X times without pickup. Often **61* or *92.
On unreachable — forward when the phone is off, out of service, or not connected to the network. Often **62*.

Use conditional when: you want to answer calls yourself when you can, and only forward the ones you miss.

How long does it take to kick in?

For star codes: immediately. You dial the code, hear a confirmation tone, it's live.

For VoIP portals (RingCentral, Dialpad, 8x8, etc.): usually 30 seconds to 2 minutes after you save. Sometimes requires signing out and back into the mobile app.

Always test from a different phone after you set it up. That's the only way to be sure.

What does call forwarding cost?

On modern unlimited plans: nothing. Every major US wireless carrier (Verizon, AT&T, T-Mobile) includes forwarding free on unlimited plans. Forwarded calls don't count against any minute bucket because unlimited plans don't have minute buckets.

On limited-minute plans (pay-as-you-go, some business plans): forwarded calls may consume your minutes on both the inbound leg (ringing in) and the outbound leg (routing to the forward destination). Worth checking.

On business VoIP plans: forwarding to US destinations is almost always free. Forwarding to international numbers often has a per-minute charge.

On landlines: usually a small monthly add-on ($2–5/mo) unless you have a bundled business package.

The "which number rings" question

One thing that confuses people: when you forward calls, your caller ID still shows the original caller, not your number. So if a customer calls your business line 555-BUSINESS, and you've forwarded that to an AI receptionist at 555-AI-RECEPT, the AI sees "incoming call from 555-CUSTOMER." It does not see "incoming call from 555-BUSINESS." This matters for how your AI greets people, for call tracking, and for CRMs.

Common gotchas

Voicemail still picks up. Your voicemail delay might be shorter than your no-answer forwarding delay. Use Forward Always (unconditional) to bypass voicemail entirely, or set your voicemail delay longer than your forward timer.
"Do Not Disturb" kills forwarding. On many phones, enabling DND sends calls straight to voicemail without triggering the forward. Turn DND off when you want forwarding active.
You forgot you enabled it. Especially on star codes — the phone doesn't visually indicate forwarding is on (some phones do, most don't). If you're suddenly not getting calls, dial *73 to cancel forwarding just in case.
The destination is unreachable. If the number you're forwarding to goes to voicemail or is off, the call typically goes there. Make sure the destination is something that answers reliably — which is why AI receptionists are popular: they answer 100% of the time, 24/7.
Forwarding across carriers works. You can forward a Verizon cell to a T-Mobile cell, to a Google Voice number, to a Human Add AI phone number — it doesn't matter who owns the destination.

How to always turn forwarding off

The universal cancel code for most carriers: *73. On GSM (AT&T/T-Mobile), also try ##21# and ##004# to clear all conditional forwarding. If you're in a VoIP portal, there's usually a single "disable" toggle per number.

Forwarding to an AI receptionist?

The whole reason you're reading this is probably to stop missing calls. If you're setting up call forwarding to send calls to a voice assistant, an answering service, or an AI, the steps above are the same — you just enter their number as the forward-to destination. Human Add AI gives you a dedicated AI receptionist that answers 24/7, captures every caller's intent, and texts you the details. Try it free for 7 days →