I recently got a new Walkman Sony Ericsson w300i for free when signing up for a new wireless account for work. This phone was going to be a 'throw away' as I had an Apple iPhone to use with this account.

I decided to replace my other wireless phone (Sony Ericsson T637) with the w300i- however, the w300i was locked to the carrier, and the old sim card wouldn't work, complaining about 'Insert Correct Smartchip'.

Funny enough, I was trying to use an AT&T sim card on an AT&T branded phone. The problem is I was previously a Cingular customer (before the AT&T assimilated them).

The choices were pretty much as follows:
1. Go to the AT&T wireless store and upgrade the old sim card/account to the new one (migration, the tech support person called it). This is more complicated than I cared for this phone.
2. Find someone of dubious character and methods to network unlock the w300i - maybe get scammed and no guarantees.
3. Let the phone sit in the drawer, new and unused - a shame/waste.

Defaulted to #3 for a while.

Today I called AT&T support and explained that I was going to Europe for a trip and wanted to get the unlock code. If you ask nicely and have been a good customer (longer than 6 months or even a year), my understanding is that they will give you the unlock code.

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