Apple’s addition of dual SIM support to multiple new iPhones was one of the more interesting announcements at its Gather Round event on Wednesday, but the company waited to disclose some of the implementation details for the iPhone XS and iPhone XS Max. A new Apple support document focuses solely on the feature for the new top-of-line phones, without reference to the upcoming iPhone XR.
The feature notably won’t be supported on day one — it’s “coming later this year” to iOS 12 — and comes along with new settings, as well as a new two-tiered cellular signal indicator display. There are also some limitations on which phones and SIMs will support the feature.
- An iPhone using dual SIMs must be unlocked, unless both SIMs are from the same carrier.
- Only one of the two SIM’s carriers may be CDMA — such as Verizon or Sprint.
- For iPhones outside of China, only one SIM can be physical; the other must be an eSIM. This was disclosed during the event.
- For iPhones sold in China, both SIMs can be physical.
- Users will be able to choose a default SIM, and specify that the secondary SIM is either data-only or data with voice services — useful for travelers who don’t want to pay for cellular minutes while abroad.
- Users will also be able to specify the SIM to be used for phone calling and text messaging.
Specifics of how the eSIM will work are also interesting.
- The eSIM can be either your primary or secondary SIM.
- eSIMs will be set up using a carrier’s app, or by scanning a QR code, after using Settings > Cellular > Add Cellular Plan.
- An iPhone will be able to store multiple eSIMs, but will only be able to use one eSIM at a time.
Apple says that the feature will be added in a software update to iOS 12, which could be offered either simultaneously with or separately from Group FaceTime — a feature that has been promised by “fall.” The company is expected to hold another media event in October focused primarily on new iPad and Mac hardware, so it could debut then, or later in 2018.