I'm not sure if this will work on all phones or services. I have a Kyocera Xcursion phone and Cricket service. The phone had been shut down, and upon restart, had an unknown lock code. Took it to Cricket, called their tech support, all to no avail. I did some research of my own on the internet and came across something that worked. It said to dial 11-1111 on the phone, but do not call it. Then, it said to enter 000000 or 111111. Then it would give a programming menu, etc . When I did this on my phone, I only needed to input 11111 (5 1's, not 6). It gave me a security code button on the bottom right corner. I clicked there and it asked if I wanted to change the lock code. THEN it gives me an option to input the 6 numbers. Six 1's and six 0's did not work. I tried 6 2's, nothing. I tried 6 3's and BINGO. It asked me if I wanted to change the code, YES or NO. When clicking YES, it defaulted the lock code back to 0000. Thought I would share this little bit of info that you'd think the tech support departments would have thought of. Hope this helps!