What's the difference between call diversion and call forwarding?

Nothing — they're the same feature with different names. "Call diversion" is the standard term in the UK, EU, Australia, and India; "call forwarding" is the US term. Same network behavior, same GSM USSD codes (`**21*`, `**61*`, `##21#`), same outcomes.

Does **21* work on every carrier?

It works on every GSM carrier — AT&T wireless, T-Mobile, Cricket, Mint, Vodafone, EE, O2, Three, Rogers, Telstra, and most international networks. It does NOT work on Verizon wireless (legacy CDMA — use `*72`), most landlines (use `*72`), or Google Voice (use voice.google.com).

How do I check if call diversion is on?

Dial `*#21#` and press call to see the unconditional diversion target. `*#61#` checks no-answer diversion. The carrier returns the current setting in a popup. If diversion is off, the response says so explicitly.

Will I be charged for diverted calls?

Carrier policies vary. On most modern plans, diverted calls are billed at the standard per-minute rate from your line to the destination — typically included on unlimited plans. International or out-of-network destinations may incur additional charges. Check your specific plan.

← Help center

Call diversion codes — full reference by carrier

"Call diversion" and "call forwarding" are the same feature with two names. Same GSM USSD codes apply across the US, UK, and most international networks.

Call diversion is the UK and international term for what US carriers call call forwarding — same network feature, same GSM USSD codes. **21*<number># diverts every call to a destination number; **61*<number># diverts only when your line is busy or doesn't answer; ##21# cancels. The codes work the same on AT&T wireless, T-Mobile, Vodafone, O2, EE, Three, Telstra, Optus, Rogers — anywhere on a GSM network.

The four GSM call diversion codes

GSM defines four diversion conditions, each with its own USSD code:

`21*<number>#` — divert every** call (unconditional / always).
`67*<number>#` — divert when busy** only.
`61*<number>#` — divert when no answer** (~25 seconds).
`62*<number>#` — divert when unreachable** (phone off, no signal).

Most carriers conflate "busy" and "no answer" into a single **61* rule — handier for everyday small-business use because one code covers both common conditions.

Cancelling each diversion type

Each set rule has its own cancel:

`##21#` — cancel unconditional diversion.
`##67#` — cancel busy diversion.
`##61#` — cancel no-answer diversion.
`##62#` — cancel unreachable diversion.
`##002#` — cancel all diversion rules at once.

When in doubt about which is active, dial ##002# to start clean.

Checking the current diversion status

GSM also defines status-query codes — they return the current diversion target without changing anything:

***#21#** — what number does unconditional diversion go to?
***#61#** — what number for no-answer diversion?
***#67#** — for busy?
***#62#** — for unreachable?

Dial from your line, press call/send, the carrier replies with the current setting in a confirmation popup. Useful if you suspect forwarding was left on but don't know where calls are going.

Carriers that use these codes

GSM USSD codes work on: US — AT&T wireless, T-Mobile, Cricket, Mint Mobile, Boost (GSM), Ultra Mobile, Google Fi (T-Mobile), most other GSM MVNOs. UK — Vodafone, EE, O2, Three, Tesco Mobile, giffgaff, BT Mobile, plus most MVNOs. Canada — Rogers, Freedom Mobile, Public Mobile, Chatr, Fido. Australia — Telstra, Optus, Vodafone AU, Aldi Mobile. International — most GSM networks worldwide use the same pattern.

They don't work on CDMA networks (Verizon wireless on legacy CDMA, US Cellular, Visible CDMA-mode) or on landlines — those use the older *72 / *71 / *73 star codes instead.

Try the carrier code generator

Pick your carrier and condition — get the exact code to dial, with a copy button.

Country

Carrier

When should calls forward?

Forward to this number (your RingOwl number, your other line, etc.)

Code preview

Enter the destination number above and the dial code appears here.

FAQ

What's the difference between call diversion and call forwarding?: Nothing — they're the same feature with different names. "Call diversion" is the standard term in the UK, EU, Australia, and India; "call forwarding" is the US term. Same network behavior, same GSM USSD codes (**21*, **61*, ##21#), same outcomes.
Does **21* work on every carrier?: It works on every GSM carrier — AT&T wireless, T-Mobile, Cricket, Mint, Vodafone, EE, O2, Three, Rogers, Telstra, and most international networks. It does NOT work on Verizon wireless (legacy CDMA — use *72), most landlines (use *72), or Google Voice (use voice.google.com).
How do I check if call diversion is on?: Dial *#21# and press call to see the unconditional diversion target. *#61# checks no-answer diversion. The carrier returns the current setting in a popup. If diversion is off, the response says so explicitly.
Will I be charged for diverted calls?: Carrier policies vary. On most modern plans, diverted calls are billed at the standard per-minute rate from your line to the destination — typically included on unlimited plans. International or out-of-network destinations may incur additional charges. Check your specific plan.

Forward your line to an AI that books

RingOwl is a 24/7 AI answering service for small businesses. Forward your line with the codes above and the AI picks up every call, books appointments straight into your calendar, and texts you a summary. Free 7-day trial, no credit card.

Start your free trial →