Secret Codes guide
**05*12345678*1234*1234# on iPhone: Unblock a SIM With the PUK
By Muhammad Shahid · · 4 min read
Quick answer
**05*12345678*1234*1234#: Clear a PIN-blocked SIM using the unblocking key from your carrier. After three wrong PIN entries the SIM blocks itself and needs a PUK, the Personal Unblocking Key, which is typically eight digits and is held by your carrier. TS 22. 030 section 6. 6.
Secret CodesDial codes, SIM & network test · Free on the App StoreDownload free →| Code | **05*12345678*1234*1234# |
|---|---|
| What it does | Clear a PIN-blocked SIM using the unblocking key from your carrier. |
| Published for | AT&T, T-Mobile and any iPhone |
| Type | Support varies |
Clear a PIN-blocked SIM using the unblocking key from your carrier. This page explains what **05*12345678*1234*1234# does, how to use it on an iPhone and which carriers it applies to.
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What does **05*12345678*1234*1234# do?
After three wrong PIN entries the SIM blocks itself and needs a PUK, the Personal Unblocking Key, which is typically eight digits and is held by your carrier. TS 22.030 section 6.6.3 gives the procedure as **05*PIN_UNBLOCKING_KEY*NEW_PIN*NEW_PIN#, and the spec is explicit that a new PIN must be supplied whether or not you actually wanted to change it.
In practice an iPhone with a blocked SIM puts a PUK entry screen on the display by itself, so you rarely need to type this string. Use whichever appears.
Getting the PUK means contacting the carrier and passing account verification. AT&T and T-Mobile both provide it through support and, in some cases, through the account portal. It is not derivable from the phone number or the ICCID and no third party site can generate it.
Important: Ten consecutive wrong PUK entries destroy the SIM permanently. There is no recovery, no reset and no support call that fixes it. You will need a replacement SIM or a re-issued eSIM, and on some accounts that means losing anything stored on the card. Only ever enter a PUK your carrier gave you directly, and if you are not certain of the digits, stop and call them.
How do I use **05*12345678*1234*1234#?
- Contact your carrier and pass account verification to obtain the PUK.
- If the iPhone shows a PUK prompt, use that screen rather than the keypad.
- Enter the PUK exactly as given, then choose a new PIN and confirm it.
Which carriers does this apply to?
| Published for | AT&T, T-Mobile and any iPhone |
|---|---|
| Type | Support varies |
| Good to know | iPhone normally presents its own PUK prompt when a SIM blocks, which is the safer route. The string is documented in the spec and behaves the same way where the dialler accepts it. |
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Frequently asked questions
What does **05*12345678*1234*1234# do on iPhone?
Clear a PIN-blocked SIM using the unblocking key from your carrier. After three wrong PIN entries the SIM blocks itself and needs a PUK, the Personal Unblocking Key, which is typically eight digits and is held by your carrier. TS 22. 030 section 6. 6.
What else should I know about **05*12345678*1234*1234#?
gives the procedure as **05*PIN_UNBLOCKING_KEY*NEW_PIN*NEW_PIN#, and the spec is explicit that a new PIN must be supplied whether or not you actually wanted to change it. In practice an iPhone with a blocked SIM puts a PUK entry screen on the display by itself, so you rarely need to type this string. Use whichever appears.
What are the steps for **05*12345678*1234*1234#?
1. Contact your carrier and pass account verification to obtain the PUK. 2. If the iPhone shows a PUK prompt, use that screen rather than the keypad. 3. Enter the PUK exactly as given, then choose a new PIN and confirm it.
Where do I use **05*12345678*1234*1234#?
On the keypad of the Phone app.
Do I need to press Call after typing **05*12345678*1234*1234#?
Yes. Type it on the Phone keypad, then press the green Call button.
Is **05*12345678*1234*1234# a hidden or secret code?
No. It is a published service, not a hidden menu. iPhones do not have Android-style engineering menus.
Which carriers does **05*12345678*1234*1234# work on?
It is published for AT&T, T-Mobile and any iPhone. iPhone normally presents its own PUK prompt when a SIM blocks, which is the safer route. The string is documented in the spec and behaves the same way where the dialler accepts it.
Is there anything to watch out for with **05*12345678*1234*1234#?
Ten consecutive wrong PUK entries destroy the SIM permanently. There is no recovery, no reset and no support call that fixes it. You will need a replacement SIM or a re-issued eSIM, and on some accounts that means losing anything stored on the card. Only ever enter a PUK your carrier gave you directly, and if you are not certain of the digits, stop and call them.
Does **05*12345678*1234*1234# work on Android phones too?
It is handled by the carrier or service rather than the iPhone, so it is not tied to one phone brand. Check with your carrier.
Will **05*12345678*1234*1234# work outside the US?
It is published for US carriers and services, so do not count on it abroad. Ask your carrier before you travel.
What if **05*12345678*1234*1234# does not work on my iPhone?
Check that it applies to your carrier first, because carriers decide which services they offer and can change them. If it should apply to your line, contact your carrier.
What is related to **05*12345678*1234*1234#?
**042*0000*1234*1234#: Change Your SIM PIN2. Change the second SIM PIN that guards fixed dialling and similar features.
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