What is a SIM lock?

SIM lock (also known as simlock, network lock or subsidy lock) is a common feature of all GSM phones, like iPhones for example. SIM lock is built into GSM by cell phone manufacturers (like Apple) and Carriers use it in order to prevent their customers from using the phone to other countries or mobile networks.

This is how SIM lock works

Most of the times, when you buy an iPhone is SIM locked. This means that the phone accepts only one SIM card as indicated by International Mobile Subscriber Identities (IMSIs).

In simple words a SIM locked GSM phone can only use:

    1. A SIM card that was issued to a specific country (MCC: Mobile country code)
    2. A specific Carrier (MNC: Mobile network code)
    3. One SIM card (MSIN: Mobile subscriber identification number)

What is the real reason behind SIM lock?

SIM locking stops you from using a new or different SIM Card and this is extremely important for the prepaid contract offers that Mobile Networks do.

Usually, a Carrier offers a phone at a discount as long as the customer signs a contract to use only this Mobile Network for a specific period of time (mostly 1 to 3 years). SIMlock ensures the Carrier that the customer won’t be able to:SIM lock-sim-card types

    • Break the contract
    • Stop paying the monthly fees
    • Find a cheaper plan and use another Mobile Network
    • Use the iPhone to another country
    • Sell the iPhone

    How can someone remove the SIM lock?

    On the other hand phones without the simlock feature are called SIM free or unlocked. These phones do not subject to any SIM restrictions. You can remove the SIM lock from a phone by:

    • Asking the Carrier, after a certain amount of time (it depends on the contract you signed and you will need a lot of paperwork in most cases)
    • Using third party SIM lock Removal Services ( Unlocking a phone is legal in most parts of the world)

    If you choose the later the best iPhone Unlock Solution is the Official IMEI Unlock Method!

    Related articles from iPhone Unlock category:


      1. Makis ( User Karma: 11 ) says:

        Hi, Schriebl!

        Of course, it is possible but which Carrier Locked your iPhone 7?

        We are not an iPhone Unlock Provider but a blog that helps people to unlock their iPhone safe and guaranteed with the best iPhone Unlock Providers!

        Anyway, go to UnlockSpector to check your IMEI and the guys there will reveal everything about your iPhone and suggest you the most suited IMEI Unlock Services for your exact situation (and how much it will cost you)

        I hope, I’ve helped!
        Take care Schriebl and come back to tell me how it went!

    1. Mitch says:

      Hi guys I have a iPhone 5s that’s network locked to Optus Australia can this be unlocked
      Imie = 352020063283222 thanks

    2. Daniel Houck says:

      I was sold two IPhone6S that are SIM locked to Movistar Chile. These phones are NEW, never activated. I am in Mexico and Movistar Mexico has told me they cannot activate the phones. They must first be SIM unlocked. AppleCare has been assisting me and it is they who informed me where the phones originated. AppleCare also checked the IMEI numbers and confirmed the phones are NOT blacklisted. They may be surplus or closeout stock from Movistar Chile.

      Here are the IMEI numbers:

      Since the phones were never activated and have no SIM chips, I would have to unlock them by hooking them up to a computer or ITunes somehow. Do you have an unlock method for never activated phones? Could you describe briefly in simple terms? Thank you.

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