How to Configure Dual eSIM in iOS 16

Apple’s iOS 16 allows users with compatible iPhone models to activate and operate two cellular plans simultaneously using dual eSIM technology, completely removing the requirement for a physical nano-SIM card. This configuration enables seamless management of personal and business lines or local and travel data plans directly from the device's settings. Below is a direct guide on how dual eSIM management works, how to set up two active profiles, and how to manage data, voice, and messaging preferences.

Device Compatibility and Requirements

To run two active eSIMs simultaneously in iOS 16, you need an iPhone 13 series, iPhone 14 series, or later model. Older dual-SIM iPhones (such as iPhone XS through iPhone 12) support multiple stored eSIM profiles, but they only allow one active eSIM alongside one physical nano-SIM. Both cellular carriers must support eSIM activation.

Activating the Second eSIM Profile

  1. Open Settings on your iPhone.
  2. Tap Cellular (or Mobile Data depending on your region).
  3. Tap Add eSIM or Set Up Cellular.
  4. Choose your activation method:
    • Transfer From Nearby iPhone: Moves an existing eSIM from another device using Bluetooth and your Apple ID.
    • Use QR Code: Scans the activation code provided by your carrier.
    • Carrier App or Manual Details: Enters SM-DP+ address and activation codes provided directly by the network operator.
  5. Follow the on-screen prompts to complete the carrier's profile installation.

Labeling Your Cellular Plans

Once both eSIM profiles are installed, iOS 16 prompts you to label each line to help you distinguish between them:

  1. Select a preset label (such as Primary, Secondary, Personal, Business, or Travel), or create a custom label.
  2. Tap Done to save your labels. These labels will appear across the system, including in the Phone and Messages apps, showing which line is being used.

Setting Default Lines for Calls, Messages, and Data

During setup or afterward in Settings > Cellular, you configure how iOS allocates system resources between the two lines:

  • Default Line (Voice and SMS): Choose which line handles outgoing calls and SMS messages to contacts not assigned to a specific line. You can change the line for an individual contact inside their contact card.
  • iMessage & FaceTime: Select which line (or both) associates with your Apple ID for incoming and outgoing FaceTime calls and iMessages.
  • Cellular Data: Choose which line provides your primary internet connection. Only one line can use cellular data at a time.

Enabling Cellular Data Switching

Under Settings > Cellular > Cellular Data, you can enable Allow Cellular Data Switching. When enabled, if you are on a phone call using your secondary line (which does not normally handle data), iOS 16 will temporarily route mobile data through that line for the duration of the call. If disabled, data is blocked while you are actively on a call on the non-data line.

Switching Between eSIM Lines in Daily Use

  • Making Calls: Open the Phone app keypad, tap the current line badge at the top of the screen, and select the alternate line before dialing.
  • Sending Messages: In the Messages app, start a new conversation and tap the line indicator above the recipient field to switch carriers.
  • Toggling Lines: In Settings > Cellular, tap any installed eSIM under the "SIMs" section and toggle Turn On This Line to temporarily disable or enable a line without deleting the profile.