Why you need unlock codes for smartphone sim card / mobile phone and what is mobile locking and how to sim unlock android phone. Before we come to know how to get sim network unlock codes for smartphone sim. First understand what mobile sim is locking. Mobile locking is normally done by gsm sim provider and many times mobile locking is a combine effort of mobile manufacturer and gsm sim provider. Many gsm sim providers like tmobile, at&t sell lg Samsung mobile on 2 year financial contract. In those cases you just need to pay every month few dollars, pound or euro to get new mobile phone of lg, samsung, htc and many branded companies mobile. T-mobile lg g5 mobile, t mobile lg g3, g2 android phone,lg k10, k7 mobile from at&t and t-mobile are available on discount or monthly installment base. This lg mobile are sim locked and you need unlock code for sim card if you want to use it on another gsm sim network. Samsung galaxy note 5, note 4 galaxy note 3 also sell in locked condition with at&t and tmobile sim. Galaxy s7 edge s7 active at&t locked, galaxy s6 edge, s6 active sim locked t-mobile also sell on discount. And to use above smartphone with other sim card you need unlock codes for that smartphones sim. Many of htc sim locked mobile are also require sim unlocking codes to use with foreign sim card. Now to secure their payment they sell mobile phone in locked condition. And after you pay all your monthly installments amount, you can unlock your mobile phone. And in that case you are provided free unlock codes for sim card from your gsm sim provider. And to get unlock codes you just need to call customer care number and explain that there is no due of payment from your side and you need to use another sim. And they provide free unlock codes for your smartphone. Before we continue to unlocking your smartphone first we learn how to check mobile is locked or not.How to know mobile is locked- If your smartphone is from at&t, t mobile, us cellular, tracfone then there is a logo on the back side of your android phone and when you power on your mobile it shows logo of sim company.- When you insert new sim of other gsm company, on mobile screen you will get message that invalid sim card, wrong sim card, network locked sim card inserted, contact service provider, enter sim network unlock pin or enter mobile sim unlock code.How to unlock mobile phone / smartphoneTo unlock smartphone / mobile, you need to generate unlock code from smartphone imei number. There are normally four kind of unlock code generated from imei number of your android smartphone. 1. Nck =network unlock code / network carrier code. Many time when you insert new sim to locked android mobile, on mobile screen new dialog box ask for sim network unlock pin. In that case you should enter nck code. In most of the time unlock code is nck /network unlock code / network carrier code. Depending upon your mobile whether lg or samsung android, your nck code is about 8 to 16 digits. Normally lg mobile ask for lg sim network unlock pin and samsung smartphone also ask for samsung sim network unlock pin that is your nck unlock code. 2. Spck= service provider unlock codes. Many times you require to enter spck code. Many sim network require both nck and spck code. So first you enter nck network unlock code and then service provider unlock code. 3. Sck= sub provider unlock code. Many of sim provider use at&t, bell, tenus, and t-mobile gsm network as a parent network and other sim provider have only sub network. In that case instead of spck code you should enter sck code sub providers unlock code. 4. Defreeze code / unfreeze code = many time your mobile got hard locked or freezed. It happen when you have roaming lock or you may entered wrong unlock pin for more than 10 times. And it permanently locks your android smartphone. And to unlock your android or to unlock hard locked smartphone you should first enter sim unlock code and then enter defreeze code to permanently unlock your android smartphone. If you have backberry mobile then unlock code will be mep1,2,3,4. Mep2 is a network unlock code and mep4 is a sim provider unlock code.How to get sim network unlock pin for smartphone. There are many free tool and apps online available to generate sim network unlock code for your android smartphone. Go to search result upto 5, 6 page. There are many smartphone models wise software to get sim network unlock pin for your smartphone. Each model has its own sim network unlock code generator tool software so it is difficult to recommend any particular tool. To get sim network unlock code for your android smartphone you require following information. 1) Imei no of your smartphone mobile. 2) Mobile country code / mcc– there is an international standard number for each country. For United States of America=310, United Kingdom=234, Canada= 302, France=208, Australia=505. 3) Mobile network code/ mnc – there is a mnc code for each gsm sim provider like at&t, t mobile, o2 uk, orange, sprint, bell and telus.T-mobile mnc for America=26 there are 2 to 3 mobile network code for t-mobile USA. Germany t-mobile mnc=262.At&t mnc code= 070,090.Telus Canada mnc=220,221Bell Canada mnc=640,651O2 uk mobile network code=2, Vodafone uk=15, Vodafone Australia=3.O2 Ireland=2. O2 Germany =7,8. 4) Make and specific model of your smartphone android. For example lg g2, lg g3, lg v10, LG g5 se h845 and H840, lg g5 lite, lg g5 all models H820, H830, H840, H850 and lg g5 friend. Here is how to unlock lg g5 models without sim network unlock pin codes. For samsung models Galaxy note3 n9000, note3 9000, note3 9005, note3 n900a, note3 n900t, galaxy note 3 n900wt. Samsung galaxy note5, galaxy note5 sm-n920t, note 5 sm-920w8, note 5 sm-n920a and galaxy note4 sm-910t, note4, sm-n910w8,n910t, 910s,910c,910a models. This method for how to unlock samsung galaxy note5 without sim network unlock pin. In this method you don’t need to generate sim network unlock pin for smartphone. You unlock it from service mode of your galaxy note5 smartphone. 5) Android version installed on your smartphone – kitkat, lollipop, marshmallow and particular version of android os. Kitkat version 4.4 -4.4.4, lollipop version5.0 -5.1.1 and marshmallow version 6.0 -6.0.1. Even each mobile manufacturer has default unlock code which is known as factory unlock code for smartphone or manufacturer unlock code. These are like 0000000, 11111111, 12345678 etc. but now a days this code are not working. Or many time mobile seller change this code with their locking codes. And when you purchase sim locked mobile, this factory manufacturer unlock code are disabled or changed with sim locking codes.