The compatibility of Subscriber Identity Module (SIM) cards between devices running different operating systems, specifically Android and iOS, is generally maintained. SIM cards, regardless of the phone’s operating system, adhere to standardized sizes and functionalities. The primary purpose of a SIM card is to authenticate a mobile device on a cellular network, allowing access to services like calls, texts, and data. Therefore, a SIM card provisioned for use in an Android phone can physically be inserted into an iPhone, and vice versa, assuming the SIM card size is compatible with the receiving device.
The interchangeability of SIM cards provides flexibility for users switching between phones. This ability facilitates using a temporary or backup device without needing to contact a mobile carrier for a new SIM card. Prior to the standardization of SIM sizes, adaptors were commonly used to accommodate different SIM card dimensions. However, modern devices predominantly utilize Nano-SIM cards, reducing the need for adaptors in many situations.