Secret phone codes that actually work (and what they really do)

You've probably seen one of those lists of "secret phone codes" promising to reveal whether you're being spied on, whether your phone is "tapped" or whether someone is reading your messages. Most of those lists mix real codes with myths, and the result is people dialling combinations that do nothing — or worse, drawing the wrong conclusions. Let's set the record straight: these are the codes that do work, what each one does, and above all how to use them for something genuinely useful: detecting call diversions you never activated, a technique scammers really do use.

What are these codes and why do they work?

They're not hidden tricks or backdoors: they're MMI codes, standard commands of GSM networks that any phone understands. You dial them from the phone app, as if they were a number, and they query or change network services: caller ID, call forwarding, call waiting. That's why they work the same on Android and iPhone, and with any carrier: they depend on the standard, not the manufacturer.

That's also how to separate the wheat from the chaff: if a code doesn't correspond to a standard network service, it most likely does nothing on your phone.

The codes that actually work, one by one

Three quick notes:

• *#06# deserves a minute right now: write your IMEI down somewhere safe. If your phone gets stolen, your carrier and the police will ask for it to block the device, and it's far easier to have it noted than to dig it out of the box or the receipt.
• #31# is the privacy code par excellence: calling a listing or a stranger without showing your number. It has its own article covering the permanent settings, the equivalents in other countries (141 in the UK, *67 in North America) and its limits: how to hide your number when calling.
• The query codes (the ones starting with *#) change nothing: they only show the status of a service. You can dial them without fear.

Why should you care about call forwarding?

This is where the real value of the list lies — and what "spy code" lists usually get wrong. A call diversion makes calls meant for you ring on another number. It's a useful, legitimate service (forwarding to your home landline, or to a colleague while you're on holiday), but it's also a tool scammers exploit when they manage to activate it on your line.

How do they use it? Two real examples from the fraud world:

• Capturing your verifications. Many services verify your identity with a phone call. If a scammer activates a diversion on your line, that verification call rings on their phone, not yours — and they can complete processes while posing as you.
• WhatsApp account hijacking. A well-known variant combines social engineering with diversions: the scammer tricks you into dialling a forwarding code (sometimes disguised as a "code to fix a problem"), redirects your calls to a number of theirs or to voicemail, and uses WhatsApp's call-based verification to register your account on their phone.

Hence a simple rule: never dial codes that a stranger dictates to you over the phone, no matter whether they claim to be your carrier or tech support. If a call like that has left you uneasy, run through the protocol in what to do about a suspicious call.

How do I check for a diversion I didn't set up?

It's a one-minute check and costs nothing:

1. Dial *#21# and press call. You'll see whether unconditional forwarding is active and, if so, to which number.
2. Dial *#61#, *#62# and *#67# to review the conditional diversions. Heads up: it's normal for *#61# or *#62# to show an unfamiliar number, because that's exactly how your voicemail works — as a diversion to your carrier's voicemail number.
3. If a diversion shows up pointing to a number you don't recognise and that isn't your voicemail, check it before anything else: look it up in the spam number directory to see if it has reports, and check its origin in our dialling code guide.

Found a diversion that shouldn't be there? Act in this order:

• Cancel everything by dialling ##002#. This removes any active diversion on the line (you'll need to reactivate voicemail if you were using it; your carrier does it in a moment).
• Change the passwords of the important accounts tied to your number (banking, email, WhatsApp) and turn on two-step verification wherever you can.
• Tell your carrier there's been an unauthorised diversion, so they can review the line and rule out other changes.

Does *#21# tell me whether my phone is tapped?

No — and this is the most repeated myth in every "secret codes" list. Dialling *#21# tells you exactly one thing: whether you have call forwarding switched on. Nothing more.

A real phone intercept — the kind authorities can authorise in an investigation — happens in the network, not on your handset, and leaves no visible trace in these codes or in any menu on your phone. No MMI code can detect it, and anyone selling you otherwise, in a video or an app, is deceiving you. The same goes for spyware installed on the phone itself: that isn't detected with network codes, but by reviewing installed apps and permissions — or with a factory reset in serious cases.

The fact that an unknown diversion is a bad sign (it is, and you now know how to clean it up) doesn't turn *#21# into a spy detector. They're different things.

Frequently asked questions

Can I break anything by dialling these codes? The query codes (*#21#, *#61#, *#62#, *#67#, *#43#, *#06#) change nothing. The only one on this list that modifies your line is ##002#, which cancels all forwarding — voicemail included.

*I dialled #62# and an unknown number came up. Have I been hacked? Almost certainly not: that's usually your carrier's voicemail number, because voicemail is technically a diversion. If in doubt, ask your carrier whether the number is theirs.

Do these codes work on iPhone? Yes. They're network codes, not operating-system ones: they work the same on iPhone and Android.

Are there codes to read someone else's messages or see their location? No. No MMI code gives access to another phone's data. Any list promising that is mixing myths in with the real codes in this guide.

In short

The real "secret codes" are few, public and boring: checking your IMEI, hiding your number, and managing forwarding and call waiting. Their value isn't in any supposed spy-hunting — it's in basic hygiene: noting down your IMEI in case your phone is stolen, and checking now and then, with *#21# and friends, that nobody has slipped a diversion onto your line. If a strange one shows up: ##002#, fresh passwords, and a call to your carrier.

And when the suspicious number isn't in a diversion but calling you, the check is even easier: look it up in NoCall's spam number directory and see whether other users have already reported it. If a nuisance number has called you, report it: every warning makes it easier for the next person.