How To Make A Sim Card Work In Another Phone. If they give it to you then go ahead and insert your new SIM card into the phone. It costs 999 to get a new SIM.

So looking at the question on if i switch my sim card to a different phone will text messages be on it the messages will still be in the phone but not the sim card. The only answer I can provide is to buy an Unlocked phone. Talk and SMS will work instantly however Data and MMS use APNs that need to be installed.
Need to switch SIM card from ATT to unlocked Xfinity phone what to do and whats to expect try putting it in says Network block SIM card do I get the PUK code and that should make it work.
You will need to call ATT and ask them for the unlock code for your phone. Select the penultimate option Settings from the drop-down list choose Contacts and then tap Import. Clean the SIM card by blowing off dust or use a soft cloth to carefully remove any residue from the gold contact area dont use soap or anything abrasive. You will need to call ATT and ask them for the unlock code for your phone.

