Telephony IDs

Android devices with SIM cards and eSIMs use the following IDs in the telephony APIs, including TelephonyManager and SubscriptionManager:

  • Subscription ID: unique ID for a mobile subscription.
  • Logical slot index or ID: unique index referring to a logical SIM slot. Logical slot IDs start at 0 and go up depending on the number of supported active slots on a device. For example, a dual-SIM device typically has slot 0 and slot 1. If a device has multiple physical slots but only supports one active slot, it will have only the logical slot ID 0.
  • Physical slot index or ID: unique index referring to a physical SIM slot. Physical slot IDs start at 0 and go up depending on the number of physical slots on the device. This differs from the number of logical slots a device has, which corresponds to the number of active slots a device is capable of using. For example, a device which switches between dual-SIM and single-SIM mode may always have two physical slots, but in single-SIM mode it will have only one logical slot.
  • Card ID: unique ID used to identify a UiccCard.

A diagram of how IDs are used in a case with two logical slots and three physical slots

In the above diagram:

  • The device has two logical slots.
  • In physical slot 0 there is a physical UICC card with an active profile.
  • In physical slot 2 is an eUICC with an active profile.
  • Physical slot 1 is not currently in use.

A diagram of how IDs are used in a case with three logical slots and two physical slots

In the above diagram:

  • The device has three logical slots.
  • In physical slot 0 there is a physical UICC card with an active profile.
  • In physical slot 1 is an eUICC that has two downloaded profiles, both active using MEP (Multiple Enabled Profiles).