Unlock network at&t gophone

You should purchase an unlock code for ZTE. Online Phone Unlocking Services MySimUnlock net

You don't unlock with a new sim card. If you want to change carriers, you'll have to use a phone on their network. If you travel to many different countries, then buy an unlocked phone before you change sim cards.

So the easiest way to tell right away if you are buying a locked or unlocked device is where you are buying it from. Generally speaking if you buy a phone from a carrier directly (AT&T, Verizon, Tmobile) you are buying a phone stamped with that brand and locked to that carrier.

Now factory unlocked devices exist but are primarily bought directly from the manufacturer. So for example you want a unlocked new iPhone 5s, for this you would buy it from Apple directly. Then you can use it with whatever Carrier you want (that also supports the 5s phone).

The good news is AT&T does allow you to unlock your devices as long as you meet certain requirements. I had my Lumia 900 unlocked after about a year of using it on my GoPhone account. You just have to head over to this link: To make this short you need a code you need to call your phone company

I think your Samsung Blackjack is locked with some particular network.You need to unlock it to use other networks.To unlock you can approach Theunlockarena.com and specify the country,locked network.Based on the availability you can get the unlcok code along with free instructions.Once unlocked you can swap networks.

you can get the codes from here to unlock your phone. Superunlockcodes.com. this site also has instructions to unlock it.

try this, it should work for the samsung sgh-a137. First insert the T-Moble SIM in phone, at WRONG CARD screen ENTER on the keypad
*2767*3855# (wait 10-15 seconds) phone will reboot(restart)
When phone completes reboot ENTER
*7465625*638*00000000*00000000#
NEXT ENTER
#7465625*638*00000000#
AND THEN *#7465625# to check the locks....all locks are inactive...these are all the locks...
network lock - inactive
subset lock - inactive
sp lock - inactive
cp lock - inactive
sim lock - inactive
activa lock - inactive
phone lock - inactive
auto network - inactive
auto subset lock - inactive
auto sp lock - inactive
auto cp lock - inactive

It's normal since your phone still locked. You must unlock your phone first with lg neon unlock code for your phone network carrier. This code will reset your phone network to default factory setting so you can put any sim card on that phone. Lg unlock code can be purchased at third party sites on internet.