Number forwarding without breaking the client's phone
Number forwarding is the 30-second step that either makes the AI receptionist go live cleanly, or breaks the customer's business phone in a way that takes a frantic call to their carrier to undo. This is the practical guide to forwarding without incidents — what to test, what to avoid, and how to back out fast if needed.
The two forwarding patterns
Modern US business phones split into two camps:
- Traditional landlines (POTS, copper) or some VoIP services that emulate POTS — use carrier-side forwarding via star codes like
*72to enable and*73to disable. The forwarding happens at the carrier; the customer's phone behavior is unchanged. - VoIP / cell / hosted PBX (RingCentral, 8x8, Vonage, Dialpad, Grasshopper, Google Voice, mobile lines) — forwarding is configured inside the provider's admin panel, not via star codes. Each provider has a different UI.
Get the wrong pattern and the customer dials a star code that does nothing (or activates a feature they don't want), and you spend 20 minutes diagnosing.
Pre-flight: identify the carrier
Before sending forwarding instructions, ask: "Who's your phone carrier or service?" The answer tells you which pattern.
Common answers and their pattern:
| Carrier / Service | Pattern |
|---|---|
| AT&T traditional landline | *72 star codes |
| Verizon traditional landline | *72 star codes |
| Spectrum / Charter Voice (residential/SMB) | *72 star codes (sometimes admin panel) |
| Comcast Business Voice | Admin panel (Comcast Business portal) |
| RingCentral | Admin panel |
| Vonage / 8x8 / Dialpad | Admin panel |
| Grasshopper / Google Voice | Admin panel |
| Cell phone (T-Mobile, AT&T, Verizon mobile) | **21*[number]# (varies by carrier) |
If you don't know, default to: "On most landlines you dial *72 + the new number, wait for the confirmation tone, hang up. If that doesn't work, check your provider's admin panel under 'call forwarding.' Send me a note and I'll walk you through it."
The *72 happy path
For landlines + landline-emulating VoIP:
- Customer picks up their business phone (the line that's being forwarded).
- Dials
*72. - Hears a tone. Dials the new RingReady number (with area code).
- Hears a confirmation tone or recorded message.
- Hangs up.
That's it. Calls to their business line now route to the AI. The original number is unchanged; anyone calling it still gets through, just via the new path.
To turn it off: *73
Same phone, dial *73, hear confirmation tone, hang up. Forwarding is disabled, calls go back to the original phone. Test this before you go live so the customer knows the back-out exists.
The VoIP admin-panel path
Each provider has a slightly different UI. The common workflow:
- Customer logs in to their VoIP admin (RingCentral / Vonage / etc.).
- Navigates to: Call Handling, or Call Forwarding, or Routing Rules.
- Adds a forwarding rule: All Calls (or Unanswered Calls) → forward to [new RingReady number].
- Saves. Tests by calling their own business number from a different phone.
You should have screenshots prepared for the 3–4 VoIP providers your niche customers use most often. A 30-second walkthrough screenshot saves a 20-minute call.
The "do not accidentally double-bill" trap
If the customer was already using an answering service or another AI receptionist, make sure they cancel the old one after confirming the new forwarding works — not before. If they cancel the old service first and the new forwarding fails, they have zero coverage for a window.
Sequence:
- Set up RingReady receptionist.
- Customer activates forwarding to RingReady.
- Call their business line from outside and confirm AI answers.
- Send 3 test scenarios through; review the email summaries.
- Once confirmed working: customer cancels the prior service.
What to test before going live
- Inbound call routing. Call the business number from an external phone. Does the AI answer?
- Caller ID. Does the AI see the right caller ID, or does it see "Unknown"? (This matters for follow-up calls.)
- Internal calls. If the customer has multiple phones in the office, do calls between internal phones still work? Forwarding shouldn't affect this; if it does, the carrier setup is wrong.
- Outbound calls. Can the customer still make outbound calls from their business phone? They should. Forwarding only affects inbound.
- Voicemail. If the customer had voicemail on the business line, does it still work for calls that drop? Usually yes, but worth confirming.
Emergency back-out
If anything's wrong, the customer dials *73 (landline) or removes the forwarding rule (VoIP) and they're back to their original setup in 30 seconds. Test this with them on the activation call so they know they're not locked in.
The conversation script for activation
"Pick up your business phone. Dial *72, wait for the tone, dial [new number], wait for confirmation. Hang up. I'm going to call you from a different number in 30 seconds — you should hear the AI answer instead of your phone ringing. If you want to undo it: same phone, dial *73, you're back to normal."
Walk the customer through this live the first time. Once they've done it once, they trust the process. The forwarding step is the moment most customers feel the most fear; you handle it personally, you build the trust that retains them.