Question about subsidy unlock codes

I have been looking online for the subsidy unlock code for my xenon, and can't find a free one anywhere. I have seen post saying to call AT&T's customer service number to get it. Is there somewhere online to get the code for free? Or if I do call, do I just ask for the code and they give it to me? This is my first LG and my first venture into modifying my phone. Just trying to get my phone to do more without screwing it up.

Unlocking a phone simply lets you use it on different networks with the right SIM card. GSM carriers like ATT and T-Mobile use SIM cards, but you need a SIM card from the company to use their network. Say I want to use T-Mobile, I put in their card. Verizon and Sprint are CDMA carriers, meaning they use a different technology, and only special phones can use the network.

Unlocking won't let you access any different towers, or change anything other than using different GSM company's SIM cards.

And the reason you need to call your carrier, is because each phone has a different unlocking number, generated by the IMEI, or identification number. They give you the special number that particular phone needs to be unlocked.

I hope this clears some stuff up.

AT&T (US) policy is if you've been a "customer in good standing" for 90+ days, they'll give you the unlock code.  They might ask you want to unlock it... in which case the proper answer is that you're planning to travel out of country and would like to be able to use your phone with local carriers in the country you're going to (there are many countries that AT&T doesn't have agreements with, though they have compatible cell networks).

There is nothing illegal about unlocking phones.  The reason why unlocked phones cost more is that often times a special hardware box is required to unlock the phone - and those hardware boxes cost a lot of money.

The reason why the carriers lock the phone to begin with is to protect their "investment" in your equipment.  The GR500 that you get for $50 with 2-year activation or upgrade normally costs $300+ without contract.  Your carrier pays the difference as a method to keep you as a paying customer for the next 2 years.

They lock the phone to their network so you don't just do an upgrade at minimal price and later cancel service or move to take the phone to another carrier.

In many respects it's a bit of flawed logic since moving to another carrier will get you another phone at reduced price anyway...  I guess it stops the resale market, but there wouldn't be a large resale demand if the phones weren't ridiculously overpriced to begin with?  I dunno...