You can Insert a SIM card from a Samsung phone into an Apple iPhone to use the device with your existing service account. If you currently use AT&T with your Samsung phone, inserting the SIM card into any iPhone generates services. If you use the Samsung phone with a different carrier, on the other hand, its SIM card only works in unlocked, or “jailbroken,” iPhones. Warnings Writer Bio

If I Put My Samsung SIM Card in My iPhone  Will It Work  - 83