My girlfriend broke her Verizon phone. I gave her my AT&T Windows 640 GoPhone. The problem is we want to unlock it for Verizon, but. I haven't used the phone since May. So I don't remember any of the info to get an unlock code. I don't even use the same e-mail anymore. Can we still unlock the phone? Or can she just reactivate it with my SIM card?
I also don't think it can work on Verizon's older technology.
As for unlocking it, I don't know if you can unlock it as a current customer. BUT any non AT&T customer which it sounds like your girlfriend is, can unlock any AT&T phone unless AT&T is still owned money for. Not hard to find the unlock request page on their site. I've done it many times, including some new AT&T L640 GoPhones that were still in the sealed box (the info needed to request a code is on the outside of the box).
If you unlock it, and you should even if it won't work on Verizon because it will make it easier to use it another carrier should the need arise, there isn't a procedure I'm aware of (and I've searched) to unlock the 640 without an actual non AT&T sim in the phone. A lot of phones have procedures the carriers won't tell you about for unlocking with no sim, but the 640 isn't one of them.