# Cell Phone Unlocking and SIM Replacement
**URL:** https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300
**Category:** Factual Questions
**Created:** [January 31, 2006, 2:39am UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300 "2006-01-31T02:39:55Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Enright3](https://boards.straightdope.com/u/Enright3)
#### Post date: [January 31, 2006, 2:39am UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/1 "2006-01-31T02:39:55Z")
My daughter lost her phone. We’re still on an AT&T plan. Since we’re grouped together I would rather not get her a new phone through cingular as it would require all of us to obtain Cingular equipment. I don’t want that expense right now.
What I’d like to do (I think) is use an old Cingular Sony Ericsson T290a that I’m in posession of, put in a brand new AT&T SIM that I never used that I also happen to be in posession of.
1. Is this possible?
2. I assume the phone is locked? When is it illegal to unlock the phone? I read a couple of other threads that indicated it’s illegal. If I own the phone, why is it illegal to unlock it?
3. Assuming It’s NOT locked, can my AT&T SIM (never been used) be activitated, or did that go away too with the AT&T / Cingular merger?
4. Anything else I might be missing? Please add it too.
Thanks,
E3
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### Author:  [@Cleophus](https://boards.straightdope.com/u/Cleophus)
#### Post date: [January 31, 2006, 4:07am UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/2 "2006-01-31T04:07:32Z")
First, it’s not illegal to unlock your cell phone.
Second, try the phone with the SIM card. The worst that will happen is it won’t work.
If you need your phone unlocked, you can find a variety of buisnesses that will unlock it. First, check with Cingular. You may get them to provide the unlock code. If not, try some local dealers, or check [howardforums.com](http://howardforums.com) for recommendations.
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### Author:  [@Rusalka](https://boards.straightdope.com/u/Rusalka)
#### Post date: [January 31, 2006, 4:25pm UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/3 "2006-01-31T16:25:18Z")
I’m in a similar situation (phone stolen) but I don’t have an AT&T SIM chip.
1. yes it’s possible
2. you can unlock the phone, there are websites out there that have programs to help you. It took me several hours to do it with a Nokia Cingular phone. A Cingular dealer will NOT do it for you. There are some independent shops that will do it for $10-$20. Most of the time, if you fail to unlock the phone using the keypad after several tries, it will “hardlock” and require special equipment to unlock. Some of those independent shops will do that too.
3. I don’t know how you’d put her old phone number on the new SIM chip. I have the same question.
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### Author:  [@zoltar7](https://boards.straightdope.com/u/zoltar7)
#### Post date: [January 31, 2006, 4:36pm UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/4 "2006-01-31T16:36:54Z")
Can’t you just get a new SIM from Cingular? I know when I’ve lost my T-Mobile phones, they’ve given me a new SIM, no charge.
At that point you shouldn’t have unlocking issues, since you’ll have a Cingular phone and SIM.
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### Author:  [@Rusalka](https://boards.straightdope.com/u/Rusalka)
#### Post date: [January 31, 2006, 6:30pm UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/5 "2006-01-31T18:30:30Z")
His post says he doesn’t want to change to a Cingular plan. If you get a Cingular chip you have to switch from the old AT&T plan even thought they are _supposedly_ the same company.
I still would like to know how to program the AT&T SIM chip to work with the old plan.
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### Author:  [@Enright3](https://boards.straightdope.com/u/Enright3)
#### Post date: [February 1, 2006, 7:35am UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/6 "2006-02-01T07:35:52Z")
> [@Rusalka](#):
>
> I’m in a similar situation (phone stolen) but I don’t have an AT&T SIM chip.
>
> 1. yes it’s possible
> 2. you can unlock the phone, there are websites out there that have programs to help you. It took me several hours to do it with a Nokia Cingular phone. A Cingular dealer will NOT do it for you. There are some independent shops that will do it for $10-$20. Most of the time, if you fail to unlock the phone using the keypad after several tries, it will “hardlock” and require special equipment to unlock. Some of those independent shops will do that too.
> 3. I don’t know how you’d put her old phone number on the new SIM chip. I have the same question.
As far as #3 is concerned… The rep at the Cingular/AT&T helpdesk told me yesterday that if I had the phone he could get me a SIM chip, and set me up in a couple of minutes. I just happen to have have one already (A SIM, Not an AT&T Phone). But you can buy brand new AT&T SIMS on the internet for $5 or $6.
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### Author:  [@Rusalka](https://boards.straightdope.com/u/Rusalka)
#### Post date: [February 1, 2006, 6:30pm UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/7 "2006-02-01T18:30:10Z")
How do they do that though? Can they beam the number to your chip somehow when you’ve put the new chip into a phone?
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### Author:  [@Rusalka](https://boards.straightdope.com/u/Rusalka)
#### Post date: [February 1, 2006, 6:31pm UTC](https://boards.straightdope.com/t/cell-phone-unlocking-and-sim-replacement/342300/8 "2006-02-01T18:31:45Z")
The Cingular rep told me they CAN’T get you a new chip, as they don’t have any more.
The phone is not a big deal, I know how to get an unlocked phone.