If you replace it with a SIM card from the same carrier, nothing changes; the device continues to function normally. If you replace it with a SIM card from another carrier while the phone is still locked to the original, it will function as a fancy iPod but will not have any of the phone's functionality. You can read more about this type of phone on the Amazon page for them.
It's important to note that once you unlock a phone you made or bought, you cannot lock it back up again without the help of some additional software. Even if you manage to get the original lock code, most likely the phone will no longer be able to accept it.
Apple's hardware warranty does not cover damage to the SIM tray or the device caused by a customized SIM card. If you cut or change your SIM card to fit a new device type, you may be unable to connect to cellular networks or use some functions. If you purchase a new iPhone and your old SIM card does not fit, contact your carrier to have them send you a new SIM card.
When switching SIM cards between devices, keep in mind that the SIM card must be the same size as the SIM card on the device. If you need a new AT SIM card, you may get one from any AT corporate shop and get it activated. Take precautions!
When you transfer your SIM card to a new phone, you retain the same cell phone service. By exchanging the SIMs, you may also utilize different phone service plans on a single unlocked phone, such as one for business and one for personal usage. Only SIM cards from a certain mobile phone provider, on the other hand, will operate on its restricted phones. You should always check with the manufacturer of your new phone to make sure it accepts other network's SIM cards.
While your SIM card will most likely not work for the new owner of your phone, it doesn't mean you should keep it in when you sell it. There are several compelling reasons to keep this important piece of plastic with you as you say goodbye to your old smartphone.
First of all, if you have activated any additional features like data plans or international calling cards, keeping your SIM card will allow you to maintain access to these services even after you switch phones. Also, because your SIM card is what identifies yourself as a legal buyer of mobile phones, removing it from the device before you hand it in for repair or disposal ensures that you won't be billed for any more services. Finally, you may want to save your SIM card as proof of identity for other services like credit cards or insurance. You can print out a copy of its contents using a computer program such as Windows Live Mail or Gmail.
As long as you aren't using any of the features on your SIM card, there's no reason why you shouldn't be able to use it with another phone. In fact, many phone manufacturers require that you remove your SIM card before recycling your device because the metal inside the phone could end up being sold separately. However, if you do decide to keep it with you as you switch phones, here are some suggestions for where to put it: under the skin of an animal (like a turtle), in a tree, or in a memory card box.
Before swapping your SIM card to the new handset, you must first activate it on the old device. If you removed it from another active device but did not disable it, it will remain active. All you have to do now is plug it into your new device. All usage will be charged to the account linked to the SIM card. Usually, this is the phone's main account, which means you will need to log in to it with your username and password.
After entering the Vodafone unlock code into your handset, you will be able to remove the present SIM and replace it with a different one. If you are unsure if you need a Vodafone unlock code for your handset, try swapping the Vodafone SIM card with a SIM from another network. If this doesn't work then you will need to get an unlock code.
SIM cards are intended to allow customers to easily transfer data from an old phone to a new phone. According to AT, you may use your old SIM card in your new phone as long as it fits. Other carriers may have different requirements for switching over data accounts between phones.