Call forwarding: codes by carrier and phone settings
Every call forwarding code you need: AT&T, T-Mobile, Verizon, iPhone, Android, conditional rules and how to turn forwarding off.
Call forwarding — also called call diverting — sends the calls placed to your usual line to another number, in this case your Kalyvox number. You keep your public number: customers dial the same one as always, and the assistant answers. This page lists activation and deactivation codes by carrier and country, the equivalent settings on iPhone and Android, and what to check when forwarding does not work.
Unconditional or conditional forwarding?
There are two logics, and the choice changes your callers' experience entirely.
- Unconditional (immediate) forwarding: every call goes straight to the assistant and your phone never rings. Use it when you are on a job, in a meeting or on the road, and you do not want to miss a single call.
- Conditional forwarding: your phone rings first, and the call only moves across if you are busy, do not answer within about 20 seconds, or are unreachable. This is the safety-net setting when you would rather pick up yourself.
Most common setup
Unconditional forwarding codes by carrier
Replace NUMBER with your Kalyvox number in international format (+1..., +33...), dial the code from the keypad like a normal call, then press call. Confirmation appears within a second or two.
| Country / Carrier | Activate | Deactivate |
|---|---|---|
| United StatesAT&T (GSM) | **21*NUMBER# | ##21# |
| T-Mobile (GSM) | **21*NUMBER# | ##21# |
| Verizon (CDMA) | *72NUMBER | *73 |
| CanadaAll carriers | *72NUMBER | *73 |
| United KingdomAll carriers | **21*NUMBER# | ##21# |
| FranceOrange | **21*NUMBER# | ##21# |
| SFR | **21*NUMBER# | ##21# |
| Bouygues Telecom | **21*NUMBER# | ##21# |
| Free Mobile | **21*NUMBER# | ##21# |
Worked example
**21*+14155550134# then call. To cancel: ##21#.These are standard GSM (USSD) codes, identical across AT&T, T-Mobile and most European carriers. Legacy CDMA networks — Verizon and most Canadian carriers — use the *72 / *73 syntax instead, with no # at the end.
Conditional forwarding codes
These codes work on GSM networks worldwide, including AT&T and T-Mobile.
| Forwarding case | Activate | Deactivate |
|---|---|---|
| Busy (you are already on a call) | **67*NUMBER# | ##67# |
| No answer (after ~20 seconds of ringing) | **61*NUMBER# | ##61# |
| Unreachable (phone off, no signal) | **62*NUMBER# | ##62# |
| All three at once | **004*NUMBER# | ##004# |
**004*NUMBER# enables all three conditions at once: the recommended setting to never lose a call while keeping the option to answer yourself.
From your phone settings
iPhone
Open Settings → Apps → Phone → Call Forwarding (older iOS: Settings → Phone → Call Forwarding), turn it on, then enter your Kalyvox number. The forwarding icon appears in the status bar. Note that this switch only handles immediate forwarding; for conditional rules, use the codes above.
Android
Open the Phone app → menu (⋮) → Settings → Calls → Call forwarding. All four cases (always, when busy, when unanswered, when unreachable) are listed and you can enter your Kalyvox number for each. The exact menu location varies by manufacturer (Samsung, Xiaomi, Google Pixel).
Landline, business line or PBX
The codes above work on most landlines. On a business plan or IP-PBX, forwarding is usually configured from the carrier's customer portal or the PBX admin interface, under "forwarding", "overflow" or "call diversion". On a multi-line system, ask your installer to route overflow calls to your Kalyvox number instead of voicemail.
Check and turn off forwarding
- Check unconditional forwarding: dial
*#21#. The screen shows whether forwarding is active and to which number. - Check every forwarding rule:
*#004#. - Turn everything off at once:
##002#. This clears all forwarding rules, including the ones pointing at your voicemail, which you may then need to re-enable.
Voicemail and forwarding
Forwarding is not working: what to check
- Number format: always use international format with the country code (+1 415..., not 415...). This is the number-one cause of rejected forwarding.
- "Connection problem" or "Service not available": forwarding is not enabled on your plan. Some prepaid and restricted plans exclude it — ask your carrier to switch it on, usually at no cost.
- Wi-Fi calling or VoLTE: temporarily turn off Wi-Fi calling, dial the code, then turn it back on.
- Dual SIM: the code applies to the default line. Make sure you are dialling from the right SIM.
- Cost: nothing changes for the caller. On the forwarded line, the forwarded leg is billed as an outgoing call under your plan, and is included in most unlimited plans.
Test before switching your real calls over
Enable forwarding, then call your usual line from another phone: the assistant should pick up within a few seconds. Have a full conversation, hang up, and check that the request shows up in your dashboard with the summary, the caller's number and the recording. This end-to-end test is the best way to validate both the carrier forwarding and your assistant's setup before going live.
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