Need AT&T phone for old sim card

Your phone appears to be non-smart old phone
Sony Ericsson T250i User Manual
Your phone does not have SD card.
Your message (SMS or MMS) ought to be on the phone memory.
You can transfer the message to SIM if not already one.
Then read the sim on newer phone.
There can be a difficulty though as most new newer phones cannot take big or regular sized SIM
Alternatively Forward the message from old phone to newer Android phone wirelessly and then store using cloud or dropbox

This is because ur new phone is not from the same company where u have t got ur SIM card. Your new phone and your SIM card's service providers are different. You will have to get this new phone unlocked which has a SIM lock.

there are a few questions you need to answer to get a better idea.

How old is the SIM?
You may need to update to a newer version SIM card to work in that particular phone.

How old or new is the phone the SIM is Working in.
This will further help determine.

Was this SIM working in that phone before?
If yes you may have a phone issue.

If no, the phone you are trying to put your SIM in may be locked to work only with a particular carrier. Therefore, your SIM does not register when you place it in that phone.

These are some reasons why your problem may occur.

Hope this helps .. Good luck

try taking out both cards and popping the battery on the phone.

Wait a few minutes and then turn the phone on with no card in it.

Turn it back off when it says no card found and insert the newer card and power it back up.

It seemed to keep a memory of the blank card.

If your not really up for the work to go through for this. You can just have T-Mobile give you a new one for your phone. The SIM card transfer you would have done would have saved only your phone book.

If you are into looking to transfer the SIM card. Call your phone maker. In most Cases its Motorola for T-Mobile.
Call them, and tell them that your trying to transfer your SIM into a newer phone. Alas, They should tell you the code to unlock your phone

Hope this helps!

take it to a shop so tech can restore your cellphone to open line

goodluck

We have the exact same problem and our SIM card starts with 8931. Do you think it will work for us??

Once a wireless company goes sim card, they never go back! Unfortunately, your old phone is worthless and they cannot attach any sort of IMEI to an account. Sorry!

How old is your current SIM-card ? There was a change in operating-voltage on the SIM-cards and its a known issue that the P990i wont accept "older" cards. Contact your provider and get a newer card. You could perhaps try one of your friends SIM-cards in your phone, before ordering a new one, if the card is newer than the one you have.