At Movical.Net we offer unlocking methods according to the carrier that locks the device. We can unlock the Samsung J3 Emerge by code or by software.
AT&T USA model is the SM-J327A, this code is unlocked by code, when you introduce a different SIM card, the phone request for the SIM network unlock PIN
Sprint and Boost Mobile model is the SM-J327P, these carriers lock the firmware and it is impossible to unlock with a code, the SM-J327P never requests the unlock code. The solution to unlock this model is by software, do not worry, we sent you a very well written email with the tutorial to unlock SM-J327P by software in a few minutes.
1. - Turn on the handset on with a SIM card not accepted by the device (your new network operator)
2. - If the card has a PIN number, enter it and press OK.
3. - The device will prompt: “Network lock”, Now enter the code and press OK.
4. - Your phone will indicate: "The operation was successful", becoming permanently unlocked.
Unfreeze code: If the code in step 3 does not work, type the secondary code and press Unlock, the phone will indicate Unlock fail, now dial the code again from step 3.