How To: SIM-Unlock Your HTC One for Free

SIM-Unlock Your HTC One for Free

Mobile carriers have been the bane of my existence for as long as I've had a phone. First, they take away unlimited data, and then when you try and switch carriers, they hold your phone hostage for a up to a week before unlocking it from their network.

There are services out there that can unlock your phone right away for a fee, but why not do the same thing right from your own home? Thanks to the people over at Sieempi, there is a way to SIM-Unlock any HTC One that is already S-Off!

What You'll Need

You'll need a couple of different things, depending on which HTC One you have:

HTC One M8

HTC One M7

Keep in mind this is only for GSM versions of the HTC One, meaning that Sprint and Verizon users are out of luck.

Step 1: Find Your IMEI Number

To get your unlock code, you are first going to need your International Mobile Station Equipment Identity number, or IMEI. When you input this into the Sieempi website, the service will tailor-make an unlock file for your phone.

To get started, you will need to open your Phone app and dial *#06#. You could also go to Settings -> About -> Phone Identity. Either way, just copy that number down somewhere.

Step 2: Creating an Unlock Code

To generate an unlock code, you are going to need to go to the Universal SIM Unlock page at Sieempi and input the following information:

  • Email address (to download the file after it's generated)
  • Phone Type: Enter HTC One M7 or HTC One M8
  • IMEI number

Once entered, click Send and wait for your Config.dat, aka your unlock code, to be emailed over.

Step 3: Prepping Your USB Drive/SD Card

It does not matter what USB drive or SD card you use, just be sure your phone can read it beforehand. To check, either place your SD Card into your M8 or attach your USB Drive into a USB OTG cable and make sure you get a notification saying your device is in Host Mode.

After that's all settled, copy the Config.dat to the main directory of your USB drive (M7) or SD card (M8), meaning, do not place it in a folder.

You can now attach your USB Drive or SD card to your One. If you are using an M7, you will need to also attach a power cable to the OTG Y-cable—your standard charging cable will do just fine here.

Step 4: Reboot into Bootloader

You are going to need to flash the config.dat file through the bootloader menu. To get there, hold down the Power and Volume Down buttons until you see the bootloader menu—this should take about 15~20 seconds.

Step 5: Flashing the Config.dat

From the bootloader menu, scroll down using the Volume Down button and highlight SIMLOCK. Press the Power button and let your One do its thing.

Image via

Once you get the Process done, reboot device? message, you are all done, so press the Volume Up button and let you device restart. You will know everything went fine after inserting your new SIM card.


If you have any connectivity issues, the first thing you should check is your APN settings. The APN, or access point name, settings are what your One uses to connect to the right cell towers. Each carrier has different settings, but BuzzMobile has a pretty extensive list that covers all major U.S. carriers.

To change your APN settings, open your Settings app, tap Mobile Data, and select Access Point Names. From there, tap the three-dot menu and select New APN to add your new settings.

Alternatively, if you have a M7, you can always flash a carrier-specific RUU to avoid any issues.

And that's all there is folks! You should now be the proud owner of a SIM-unlocked GSM HTC One. If you run into any issues, or just need help getting your APN settings down, be sure to leave me a comment.

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does the OTG cable for the M7 have to be a Y-cable (able to connect to power)?

I have only used the Y-cable. Most users say that is the only way to get it to work properly.

I have tried everything to unlock my Spring HTC M8 but it will not accept my t-mobile sim card. I cannot add APN (it is just grayed out) I have rooted the phone, got the code from the website and everything. any further suggestions would be great appreciated!

This guide is only for GSM models only, so it wouldn't work for Sprint.

oh ok, do you have any ideas what i could try for my sprint phone? or it just cant be unlocked?

my phone does take Sim card so it is GSM model. my HTC M7 is also sprint and i unlocked it and that works fine.

Question: I converted my HTC M8 over to the Google Play Edition, will this still work?

I have only tried it on Sense based ROMs, but it should work on GPE.

I finally managed to do it on my m7 using this improvised tools. Problem was that i was trying to boot from a modern usb 2.0\3.0 memory (sd init fail!!!), and when i pluged in the old usb from pic it worked! I reworked standard otg cable with one old male usb cable to give it power to run usb stick

My HTC One M7 from AT&T reads SD card fine with the powered-usb cable, but it all failed in red without the green line in the bottom.

--- SD init OK
Reading Config.dat 37bytes
Read MCCMNC file success
Open CID file fail, IMEI, SF, NAME, keycard FAIL
Process done, reboot device? ---

Reboot, insert forgin SIM and still asking for unlock code, what should I do?

I'm having this exact same problem.

SD init OK
Read MCCMNC file success
Open CID file fail
Open IMEI file fail
Open atseb file fail
Open SF file fail
Open NAME file fail
Get device IMEI success
IMEI checking...PASS!

Try inserting the SIM card, rebooting to bootloader, re-flashing the config.dat file a few times, and then rebooting.

I'm having this same problem. Nothing seems to be working.

Edit I don't know if this makes a difference, but when I go from the Fastboot menu to the Bootloader menu, this flashes up for half a second:

SD checking...
No gift file...
No image!
No image or wrong image!
No image or wrong image!

Double check your IMEI number and try a new config.dat. You are S-Off right?

Why can't it read the file from the internal memory? Isn't that viewed as /sdcard ? Or does it not mount as that in HBOOT?

The internal memory does not mount when in HBOOT

I've just unlocked my htc one m8 today with the code and it's not accepting my SIM card or my sister could and my help me I can't find jack shit that helps

Did you get an error during the flash?

Getting SD initial Fail !!!! I have an M7, when I plug my USB using OTG cable, my phone recognize it and I can see the config.dat in my flash drive. However when i get to the bootloader menu, and choose the Simlock option ,I get the SD initial Fail. Do I need superCID 11111111 like you have? mine is VID-CWS_001.

The CID doesn't matter. Is the power cable plugged in? What format is your USB drive?

shouldnt i be able to use my computers hard drive instead of the usb drive

No, it has to be a USB drive over OTG or a SD Card.

I have tried everything to unlock my HTC M8 but it will not accept my t-mobile sim card. finally got the code from gsmunlockhub and everything is done. i want to know if i root my phone do i lost my unlocking?

Would it be possible for me to use adb push instead of having an OTG. Couldnt I push it manually where I want it? if its possible, please tell me the command

Unfortunately you have to use an OTG cable.

Hello Andrew.My HTC one m7 locked.I got this response below when I tried unlocking it with the method u posted above.

  • SD init OK

Reading Config.dat 37bytes
Read MCCMNC file success
Open CID file fail,
Open IMEI fail Open SF file fail
Open NAME File fail
Get device imei success
Imei checking.........pass
Process done, reboot device? ---

Reboot, insert forgin SIM and still asking for unlock code. I have purchased two different codes and non worked. what should I do? Thanks

Place the SIM in before running the unlock code and try it again.

What ROM/firmware do you have running?

Android Revolution Hd 53.0
Sense 5.5
Kitkatt 4.4.2

Change your CID with the fastboot command fastboot oem writecid 11111111

Changed cid to 11111111, downgraded hboot to 1.44, still facing the same.

That is really strange. What is your MID. Use fastboot getvar all to check that

Model: M7UL

Do you know what format your USB drive is in? Only exFAT or FAT32 will work.

Have you ever flashed a different kernel/radio/firmware?

This works best with a completely stock phone. Re-flash a stock firmware and kernel an retry the process.

hi Andrew, I find your method inhere very interesting. I have, lets say, an upfront question. Considering that i am not an American resident, may I purchase a HTC m8 (i.e. AT&T carrier GSM versions) via Ebay and after applying this method, use the phone in Europe? Thank u in advance

That shouldn't be an issue. As long as you have an SD card and a GSM compatible network you should not run into any issues. I would do it sooner than later though. HTC can easily push out a firmware update that blocks this process from working.

it works for m7 with exhausted attempts by code?

pd: htc Vivid 4g tested and worked!


Just UNsuccessfully tried the config.dat, nothing happens when I select simlock. HTC ONE m7 just repaired by HTC, they replaced motherboard and thus my IMEI thereby requiring me to reapply the sim unlock process. Several IMEI unlock services have failed to generate unlock code on this new IMEI number.

I'm using brand new OTG cable, newly formatted USB drive, placed config.dat in the root of the flashdrive outside of any folder structure. I tried twice. Should it be tried multiple times? The unit is successfully rooted. Attempted to load firewater process, firewater says the unit has a "firewater patch" thus blocking it? Please advise or provide other avenues I can explore.

Thank you

Kernel Version:
3.4 10-g9ec8f5a
Android 4.4.2
HTC Sense 6.0
HTC SDK Level 6.20

If you device is not S-Off this process will not work. If firewater is not working for you, try and useSunShine. It does cost $25, but it should work regardless of your motherboard.

hi andrew
i had htc desire hd mobile carreir at&t .it was un locked but sim lock still held.i tried confiq.dat file..but it shows
ACE Pvt Ship s -off
Apr 12 2011,00.55.45

SD checking...
No gift file...
No image!
No image or wrong image!
No image or wrong image!
sim lock

fat 32 init ok
Open CID file fail
open mccmnc file fail
process done,reboot device?
please help me

I'm not sure about the Desire HD since I have only done this with a HTC One, but maybe check out this XDA thread.

I am not sure if this method works with One X, but it wouldn't hurt to try. Other than this, I am unaware of a surefire way to sim unlock the One X for free.

hi i unlock my At@t with code to use with t mobile but network doesn't work. I did all apn setting but there is no way to see connection ?

how can i do that, thank you

Do you see a SIM error when inserting the T-Mobile SIM? Are you on the newest OTA?

my sd card is mounted properly but once I connect the usb to the computer it gets unmounted and when I'm in bootloader I get sd card fail init any help please

im in stock tmobile firmware, s-off, bootloader unlocked any ideas?

You don't need to connect the device to a computer. If you are using an OTG cable power it through a wall charger.

hmm ok but still it's mounted while the phone is on but once I turn the phone off I get the sd card init ifailed message let me try with the cable plug in to the wall charger I'll post results

no same results sd card mounted when the phone is on and I can read content with root browser sd card has been formatted to fat32 still nothing and unplugging and plugging the phone to the wall charger makes no difference I get the sd init fail message

I turn phone back on and sd card gets mounted phone off unmounts this is really making me pull my hair

Do you have any encryption on the SD card?

This will unlock this phone regardless if it is connected or not.

OTG Y--Cable necessary? Can I not use my regular OTG Cable?

You need the Y cable because it does not rely on your phone to power the USB drive.

Hey I got a problem! it keeps saying "SD init fail! Process done, vol up to reboot!"
I tired 3 different usb sticks(NTFS & FAT32) & an HDD but same problem! HELP ME!

Doesn't work. When I restart phone all I See is a ! Mark. After a few seconds it buzzes followed by the ! Mark again. I'm holding both the power and volume down buttons

hi, i did all the steps but when i insert the new sim card it keeps saying that is a invalid sim card , any idea?
im using an htc one m8 sprint , im already s-off and rooted

Hola! El mi es un HTC Desire 510 de Boost mobile
Al realizar el procedimiento obtengo esto!
SD init OK
reading config.dat 37bytes
read MCCMNC file success
Open CID file fail
Open IMEI file fail
Open atsdeb file fail
Open SF file fail
Open NAME file fail
Check keycard fail
Process done, reboot device?
Me puedes ayudar?
Gracias y saludos.

Esta guia no functiona con el HTC Desire 510.

can i also use this instructions to my HTC ISW13HT? please help me.. my phone is S-On

S-Off is a requirement for any kind of unofficial SIM unlock process. You may want to see if sunshine works for your device.

hey there! i unlocked my HTC One M7, i got it S-Off with sunshine, but now when i enter the sim, it keeps on asking me for my Sim Unlock code, i called my carrier and they said to call the other carrier the phone is originally from (AT&T) but for some reason i think it's my carriers duty.....

so Please help?

Did you try running the SIM Unlock with the new SIM card already inserted?

Will this work allow for Mobile Data Access?

I recently had to send my m7 to HTC for repair. I finally got it back and noticed a few things:

  1. They flash reset it. A big no no (mainly no back up to old files)
  2. AT&T software is now in the phone. After getting in touch with AT&T reps, I received a SIM Unlock Pin. However, I think my T-mobile SIM is clashing with the AT&T software. Whenever I turn on Mobile Data, it reads Disconnected. I do notice that it says SIM locked when I click on the option in bootloader menu.

Any suggestions?

I have htc one m8 not dectecting sim and it shows imei error mcnnc fail cid fail wht is the solution

Have you flashed any mods onto your device?

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