A SIM card is what stores your cellphone account information (allowing the cellphone network to access your phone and number) as well as your contacts and in some cases your stored messages and files. Most cellphone service providers use SIM card technology in their cellphone handsets; only a few services offer phones that lack a removable SIM card. SIM cards are often interchangeable between locked phone handsets on the same cellphone service provider network and many will work freely in unlocked phone handsets. Generally if your SIM card is no longer functioning properly or you have lost the phone, you can get at least the SIM card for free.
Contact your cellphone service provider if your SIM card is damaged or no longer functions. You can visit a store, go online or call the service provider. If you have lost your phone, contact your cellphone service provider to get a replacement phone with SIM card.
Ask for a new SIM card if your phone still works but the existing SIM card is not working. If there is no sign of water damage, the company will send a new SIM card to you or install a new one in the store.
Purchase a new cellphone handset from your service provider. While it will cost money to purchase the new phone, you will get a free unactivated SIM card inside the phone packaging. If you want to add a new line to your existing plan and your cellphone service provider offers SIM-enabled phones, you will get a new phone with a SIM card that is ready to be activated. The cards are included in the cost of the phone or plan.