Call forwarding, explained (and the Google Voice exception)

Every receptionist you set up ends with the same final step, and it's the only one that happens on your customer's phone, not in your dashboard: forwarding their existing business number to their new receptionist's number. It sounds technical; it's usually one short dial code. This guide gives you the plain-language explanation, the codes for the major carriers, what to do when the customer uses a phone service instead of a carrier — and the one setup that genuinely doesn't work (Google Voice), so you catch it before you promise anything.

1. What call forwarding actually is

Your customer keeps the phone number they've always had — the one on their van, their signs, their Google listing. Nothing about that number changes and nobody has to reprint anything. Forwarding just tells their carrier: "when this number rings, send the call over there instead" — "over there" being the dedicated number their AI receptionist answers on. Flip it on, calls flow to the receptionist; dial the cancel code, everything's back exactly as it was. It's fully reversible and there's nothing to break.

2. The two flavors: forward everything vs. forward what they miss

Forward all calls sends every single call straight to the receptionist. Right for businesses that don't want to answer the phone at all — the owner is on jobs all day, or they're done playing receptionist.

Conditional forwarding (called "busy/no-answer forwarding") only kicks in when they don't pick up or they're already on a call. Right for businesses that still like answering when they can — the receptionist becomes their safety net for the calls they'd otherwise lose: after hours, mid-appointment, second caller while they're on the first.

Ask the customer which behavior they want before you look up any code — it's the difference between "your phone will stop ringing" and "your phone rings like always, you just stop missing calls." Most first-time customers relax noticeably when they hear the second option exists.

3. Major carriers: the dial codes

These are dialed from the customer's business phone (the number being forwarded), with the receptionist's 10-digit number in place of XXXXXXXXXX. Codes occasionally vary by plan — if one doesn't take, the carrier's support line will set it in two minutes.

Dial the code, listen for the confirmation tone or message, hang up. That's the whole install.

4. Phone services: RingCentral, Grasshopper, and friends

Plenty of small businesses don't have a plain carrier line — they run their number through a business phone service: RingCentral, Grasshopper, Ooma, Nextiva, Dialpad, Vonage, and the like. Dial codes don't apply there. Instead, forwarding is a setting inside the service's app or web portal, usually under a name like Call Handling, Call Forwarding, or Answering Rules: point it at the receptionist's number, either for all calls or as the "when unanswered" destination.

Every service buries it somewhere slightly different, so the practical play is: ask the customer which service they use, log into it together, and look for those menu names. Can't find it? Send us the provider name at hello@ring-ready.com and we'll dig up the exact clicks.

5. The Google Voice exception

One setup genuinely doesn't work, and it's better to catch it in your first conversation than at install time: Google Voice. Google Voice will only forward calls to a verified traditional carrier line, and it can't verify the kind of virtual numbers receptionists answer on — so a business whose main number lives on Google Voice has no way to route its calls to the receptionist. There's no code or workaround that fixes it.

What to do: make "how's your phone set up today?" a standard discovery question (the demo playbook bakes it in). If the answer is Google Voice, be straight with them: unfortunately the service can't work with their current setup. It's a disappointing conversation, but it's a far better one than a failed install after they've paid you.

6. Always end with a test call

• Forward-all: call the business's real number from your phone. The receptionist should answer — if a human or the old voicemail picks up, forwarding isn't on yet.
• Conditional: call the real number and have the owner let it ring out. The receptionist should catch it. Then have them answer one normally, to prove their phone still rings like always.
• Check the loop closes: after the test call, the owner should get the SMS and email summary. When they see their own test question written up in their inbox, the sale re-closes itself.

7. When it doesn't work: the 10-minute debug

A failed test call feels like one big mystery, but it's really two small ones: either the receptionist leg is broken (our side) or the forwarding leg is (the carrier's side) — and one call tells you which.

Step 2: call the business number from a different phone than the business's own. Some carriers treat a number calling itself weirdly (straight to voicemail), which produces very convincing false alarms. Then match what you hear to the list below:

• The old voicemail answers. The classic race: on "forward when missed," the carrier's voicemail and the forwarding rule are both waiting for the unanswered call — and voicemail fired first. Fix by shortening the no-answer window (AT&T/T-Mobile accept a timing variant: **61*1XXXXXXXXXX**25#, where 25 is seconds, settable in 5-second steps up to 30) or, for a business that wants every call answered by the receptionist anyway, sidestep the race entirely with forward-all. And if voicemail answers instantly only when the line is busy or the phone is off: that's a missed-call condition that never got its own forwarding switch — see the "one code or three" note in section 3 (**004* sets all three).
• It just rings and rings. Forwarding never actually activated. On AT&T/T-Mobile you can see the current forwarding state by dialing *#21# (forward-all) or *#61# (no-answer); on Verizon check the My Verizon app. If it shows off, re-dial the activation code and listen for the confirmation tone this time. If it refuses to take: some prepaid and budget carriers (Mint, Cricket, Metro, Visible, and friends) restrict or app-gate forwarding — two minutes with their support settles it.
• Busy tone, dead air — or a confused stranger answers. Almost always a mistyped destination number. Cancel forwarding (*73 or ##21#), then redo the code while reading the receptionist's number digit by digit off the dashboard.
• Works, but callers wait a long time before the AI picks up. Not broken — that's conditional forwarding doing its job: callers sit through the no-answer window first. Shorten the timer (see above) or move to forward-all if the wait bothers them.
• On RingCentral / Grasshopper-style services: calls vanish into an old menu or after-hours greeting. Rules fire in order, and an existing business-hours rule or IVR can swallow the call before your forwarding rule runs. Open the service's answering rules, move the forward to the top — and check the "closed hours" path separately, because it's usually a second rule.

Two more things worth knowing: forwarding changes can take a few minutes to propagate on some carriers, so re-test once before concluding anything; and if the customer's number sits behind an office phone system (a desk PBX), the dial codes won't apply — forwarding lives in that system's settings, and we're happy to help you find it.

If you're escalating to us, include: the carrier or phone-service name, the exact symptom from the list above, the time of your failed test call, and both numbers (the business's and the receptionist's). With those four things we can usually pinpoint the leg — and the fix — in one reply.

Stuck on a weird carrier or a setting you can't find? Partner support exists for exactly this — hello@ring-ready.com, screenshots welcome.