eSIM Activation: QR, LPA, and SM-DP+ Provisioning for Developers

What eSIM activation does at the protocol level

eSIM activation downloads a cryptographic profile from a carrier's SM-DP+ (Subscription Manager Data Preparation) server to your device's embedded Universal Integrated Circuit Card (eUICC). You scan a QR code, use carrier activation, or manually enter the SM-DP+ address and activation code. The Local Profile Assistant (LPA) on your phone parses the activation code, contacts the SM-DP+ server over HTTPS, authenticates the transaction, and downloads the encrypted profile to the eUICC. Once installed, the profile behaves like a physical SIM: it authenticates you to the network and stores your subscriber identity.

The underlying architecture is defined in GSMA SGP.22, the Remote SIM Provisioning (RSP) technical specification for consumer devices. The eUICC is a secure element soldered to your device's board. The profile contains your IMSI (International Mobile Subscriber Identity), authentication keys (Ki), and network access credentials. After installation, the eUICC presents these credentials to the mobile network during attach procedures, exactly as a physical SIM would. The difference is that you can install, switch, and delete profiles without physically handling hardware.

Activation methods: QR, carrier activation, and manual SM-DP+

Three standard methods exist for delivering the SM-DP+ address and activation code to your device:

QR code: The carrier generates a QR code encoding the SM-DP+ server address, activation code (or matching ID), and optionally a confirmation code. You scan this with your device camera during setup. Apple supports QR code activation on iPhone XS and later; Google supports it on Pixel 3a and later. The LPA parses the QR payload and initiates the profile download.

eSIM Carrier Activation: If your carrier supports it, the device can retrieve activation credentials directly from the carrier's backend without user input. On iOS, this appears as a prompt during setup or in Settings > Cellular > Add eSIM. The carrier's servers communicate with Apple's or Google's activation infrastructure to push the profile metadata to your device. Apple documents this as "eSIM Carrier Activation."

Manual SM-DP+ entry: You type the SM-DP+ address (a domain name like sm-v4-003-a-gtm.pr.go-esim.com) and activation code into Settings. This method is used when QR codes are impractical—for example, when you receive credentials via email or SMS. The format is typically:

SM-DP+ Address: sm-v4-003-a-gtm.pr.go-esim.com
Activation Code: LPA:1$sm-v4-003-a-gtm.pr.go-esim.com$ABC123XYZ

All three methods deliver the same information to the LPA. The choice depends on carrier infrastructure and user context.

Self-service activation: requirements and prerequisites

You can activate an eSIM yourself if your device is unlocked, supports eSIM, and you have the activation credentials.

Device requirements: Apple requires iPhone XS, iPhone XS Max, iPhone XR, or later. Google requires Pixel 3a or later. Both platforms require the device to be carrier-unlocked; a locked device will reject profiles from other carriers even if the eUICC hardware is capable.

Network requirements: You need Wi-Fi or, in some regions, an active cellular connection. Apple notes that "in some countries and regions, iPhone models that are eSIM only can activate without a Wi-Fi network," but this is carrier-dependent. The LPA must reach the SM-DP+ server over HTTPS, so network access is non-negotiable.

Credentials: You need the QR code, SM-DP+ address and activation code, or carrier app access. These are single-use in most implementations; once a profile is downloaded to a specific eUICC (identified by its EID hardware identifier), the activation code becomes invalid. If you factory-reset your device or switch devices, you must request new credentials from the carrier.

No carrier intervention is required during the actual download. The LPA and SM-DP+ handle mutual authentication and profile encryption automatically.

Dual-SIM behaviour: managing multiple profiles on iOS and Android

Modern devices can store multiple eSIM profiles and, in many cases, use two simultaneously.

iOS: Apple states that iPhones can store "eight or more eSIMs" but activate only one at a time alongside a physical SIM, or two eSIMs on devices without a physical SIM tray. You switch the active profile in Settings > Cellular by tapping the plan name and selecting "Turn On This Line." Deactivating a profile does not delete it; the profile remains in storage and can be reactivated without contacting the carrier.

Android: Google documents Dual SIM Dual Standby (DSDS) on Pixel 3a and later, allowing one physical SIM and one eSIM to be active concurrently. Pixel models that support it can run two active eSIM profiles simultaneously if the carrier permits. Some recent Pixel models support only eSIM; no physical SIM slot is present.

When two profiles are active, you choose which handles voice calls, SMS, and mobile data. Both remain registered with their respective networks, so you can receive calls on either number. Data switching is manual on iOS; on Android, you select the preferred data SIM in Settings > Network & internet > SIMs.

DSDS means both SIMs are in standby mode. If you are on a call on SIM A, SIM B may drop to 3G or become unreachable, depending on the device's radio architecture. This is a hardware limitation, not a software one.

Turning an eSIM back on (iOS)

If you deactivated an eSIM profile and need to re-enable it:

1. Open Settings.
2. Tap Cellular.
3. Tap the deactivated plan name. It will show "Turn On This Line" or similar.
4. Tap the toggle or button to activate.
5. Wait 10–30 seconds for the profile to register with the network.

The profile does not need to be re-downloaded. Deactivation is a state change, not a deletion. The eUICC retains the profile's cryptographic material, and reactivation is instantaneous once the network acknowledges the registration request.

If the plan does not appear in the list, it was deleted, not deactivated. You must obtain new activation credentials from the carrier and download the profile again.

Switching between physical SIM and eSIM on iPhone

To change which line handles calls, messages, or data:

1. Open Settings > Cellular.
2. Tap Cellular Data to choose the data line, or tap Default Voice Line to choose the voice/SMS line.
3. Select the desired SIM or eSIM.

Apple allows you to set "Allow Cellular Data Switching," which lets the device use the non-default line for data if the primary line has no signal. This is useful when roaming or in areas with asymmetric coverage.

For per-contact preferences, edit a contact and set "Preferred Line" to route calls to that contact via a specific SIM. This overrides the default voice line setting.

Troubleshooting activation failures

Common failure modes and their causes:

"Unable to Complete Cellular Plan Change": The device is carrier-locked. Even if the eUICC hardware is present, a locked device will reject profiles from carriers other than the locking carrier. Solution: contact the original carrier to unlock the device.

"SM-DP+ Address Not Reachable": The device cannot reach the SM-DP+ server. Verify Wi-Fi connectivity. Check that the SM-DP+ address is typed correctly (no spaces, correct domain). Some corporate or public Wi-Fi networks block non-HTTP/HTTPS ports or use captive portals that interfere with LPA communication. Switch to a different network.

"Activation Code Invalid": The code has already been used, or the profile was downloaded to a different device. SGP.22 allows an activation code to be bound to a specific EID, but does not require it; whether a given code is EID-bound is an operator deployment choice, not a property of the architecture. If you factory-reset your device, the EID remains the same, but the carrier's backend may have already marked the code as consumed. Request a new QR code or activation code from the carrier.

"Profile Installation Failed": The eUICC is full. iOS supports eight or more profiles, but some older devices or carrier-customised firmware may have lower limits. Delete unused profiles in Settings > Cellular > [plan name] > Remove Cellular Plan.

"Cellular Plan Not Activated" after installation: The profile downloaded successfully but failed network registration. This usually means the carrier's HLR (Home Location Register) has not yet provisioned your IMSI, or the profile's activation window has expired. Wait 10 minutes and toggle Airplane Mode. If the issue persists, contact the carrier; the problem is on their backend, not your device.

Manual network selection issues: After installing an eSIM, the device may not automatically select the correct network, especially in countries with multiple operators. Go to Settings > Cellular > [plan name] > Network Selection, disable Automatic, and manually select the carrier listed in your eSIM documentation.

What to do next

Verify your device model and iOS/Android version meet the minimum requirements (iPhone XS or later, Pixel 3a or later). Confirm the device is carrier-unlocked if you plan to use a profile from a different carrier. Obtain activation credentials—QR code, SM-DP+ address and code, or carrier app access—from your carrier or eSIM provider.

Follow the platform-specific activation flow: scan the QR code during setup or in Settings > Cellular > Add eSIM (iOS) or Settings > Network & internet > SIMs > Add eSIM (Android). If activation fails, check Wi-Fi connectivity first, then verify the activation code has not been used on another device.

For dual-SIM configurations, decide in advance which line will handle data and which will handle voice. You can change this later, but setting it correctly during activation avoids confusion when the device registers with both networks.

If you are integrating eSIM provisioning into an application, consult the GSMA SGP.22 specification for the full LPA command set and error codes. The consumer-facing flows documented here are simplified abstractions over a more complex protocol.