It cancels every call forwarding rule on a GSM mobile at once: unconditional, unanswered, busy and unreachable. Dial it and press call; the network confirms. It is the code to use when you do not know which rule is sending your calls elsewhere.

What is **21* used for?

21NUMBER# forwards every incoming call to the number you give, immediately, without your own phone ringing. ##21# cancels it and #21# shows whether it is on.

What does *#21# do on my phone?

It asks the network whether unconditional call forwarding is active and, on most networks, where it points. It changes nothing, so it is safe to dial whenever you suspect a forward is set.

On Verizon, 73 cancels call forwarding that was set with 72 or 71. It is Verizon's equivalent of ##002#. Other networks use the double-hash codes instead.

Why is my *72 call forwarding not working?

Usually the number format: Verizon wants 72 followed by exactly ten digits, no +1, no spaces, then call, and a two or three second wait for the confirmation. If that is right, dial 73 to clear any old forward and set it again, then test from another phone.

How do I turn call forwarding off?

On a GSM mobile dial ##002# to clear everything, or the cancel code for one rule: ##21#, ##61#, ##67# or ##62#. On Verizon dial 73; on AT&T dial #21#. It takes effect immediately.

Call forwarding codes: **21*, **61*, **67*, ##002# explained

Call forwarding codes are short sequences you dial on your own phone to tell your network where to send calls you cannot take. On a GSM network, which means every mobile network in Austria and the UK and T-Mobile in the US, **21*NUMBER# forwards every call, **61*NUMBER# forwards the ones you do not answer, **67*NUMBER# the ones that arrive while you are busy, **62*NUMBER# the ones that arrive while you have no signal, *#21# checks whether a forward is on, and ##002# switches every forward off at once. Verizon uses a different family: *72 to forward everything, *71 for busy or unanswered calls, and *73 to cancel.

Why the same codes turn up everywhere

The double-star codes are not a network's invention. They are part of the GSM standard that mobile networks have shared since the 1990s, which is why **21* works the same on A1 in Vienna, on EE in London and on T-Mobile in Chicago, and why the same code appears in a search from three different countries. What differs between networks is the small print: how long the phone rings before an unanswered call forwards, whether the diverted leg is charged, and which codes the network's own help pages bother to print.

Landlines and US carriers that grew out of the older North American system use single-star codes instead, and those do vary. Verizon's *72 and *73 are the best known.

The GSM codes, one by one

Replace NUMBER with the destination in full international format, for example +43 664 ... or +44 7700 ... without the spaces, dial the code, press call, and wait for the confirmation message.

What you want	Dial to set	Dial to check	Dial to cancel
Forward every call	`*21NUMBER#`	`*#21#`	`##21#`
Forward when you do not answer	`*61NUMBER#`	`*#61#`	`##61#`
Forward when you are busy	`*67NUMBER#`	`*#67#`	`##67#`
Forward when you are unreachable	`*62NUMBER#`	`*#62#`	`##62#`
Cancel every forward at once			`##002#`

`21*` is the one people mean by "call forwarding".** It is unconditional: your own phone does not ring at all, every call goes straight to the number you gave. Use it overnight, at weekends, or when you want someone else to be the front door.

`61is the one most small businesses actually want.** Your phone rings first, and only a call you did not pick up moves on. Some networks let you set the ring time inside the code, as**61NUMBER**20#`, where 20 is the number of seconds; where the network does not, the phone's own call settings usually have a delay option. Fifteen to twenty seconds is four or five rings, enough to answer if you can.

`67*and*62` cover the two other reasons you miss a call.** Busy means you were already on the phone; unreachable means the phone was off, flat, or out of signal. Set all three conditional rules and nothing falls through: you get first refusal on every call and every one you miss is still answered.

*`#21#and its siblings only ask.** They change nothing.#21#tells you whether unconditional forwarding is on and, on most networks, where it points;#61#,#67#and#62#` do the same for the other rules. If you have found a forward you do not remember setting, this is how you see it.

##002# is the reset button. It cancels every forwarding rule in one go, which is why it is the code to remember when something has gone wrong and you cannot tell which rule is doing it. It is also what people search for after a phone shop set up a forward to voicemail years ago and nobody wrote it down.

What ##21#, ##61# and the other double-hash codes mean

A single hash cancels on some networks and a double hash erases on others, and the difference rarely matters in practice: ##21# removes unconditional forwarding, ##61# the unanswered rule, ##67# the busy rule, ##62# the unreachable rule. If a single-hash form such as #21# is what your network prints, it does the same job on that network. When in doubt, ##002# clears everything.

The same codes, network by network

The table above is the standard; each network adds its own small print, and we keep a page per country with the carriers' own codes and caveats. Austria's three networks, with A1's 25-second ring time and Magenta's check codes, are in call forwarding codes for A1, Magenta and Drei. The US is the odd one out: Verizon uses *72, *71 and *73, AT&T *21* and #21#, and only T-Mobile takes the GSM set, all with the ten-digit number and no +1; the details are in Verizon, AT&T and T-Mobile call forwarding codes.

Why "call forwarding not working" is usually one of four things

Most failures are not the network. Check these before ringing anyone.

The number format. GSM codes want the full international form starting with +. Verizon and AT&T want exactly ten digits with nothing in front. A code that returns "invalid" or "not allowed" is nearly always the wrong form.
An older forward is still set. Two rules can point at two places. Dial ##002# (or *73 on Verizon), then set the one rule you want.
A phone cannot ring itself. Test from a different phone. Calling your own number from the forwarded phone tells you nothing.
The destination is not answering. If you forward to a number that goes to voicemail, callers land in that voicemail. Forward to something that picks up.

Where forwarded calls can go

The destination can be any number that answers: a colleague's mobile, an office line, or a service that answers for you. With PhoneMyAgent, the number you forward to is the one your AI agent answers on. It answers in your business name from your own documents, books appointments where you allow it, takes messages, and emails you a transcript after every call, and your dashboard shows the codes above for the carriers in your country with your own number already filled in. You keep the number your customers know, because forwarding never changes it. Every account starts with 45 free minutes and no card; the plans are on our pricing page.

For the fuller guide to keeping your number, see keep your number and forward your line to an AI, and for what the product is, the introduction.

What forwarding will and won't do

Forwarding moves the call, it does not move the number: ownership stays with your provider and everything printed or listed keeps working. Your provider may charge for the forwarded leg, which is a normal call charge and worth a glance at your tariff before leaving a forward on permanently. And a rule is never smarter than what you set: forward everything and your own phone stops ringing, which is the intended behaviour but surprises people the first time.