How to Check If Your Phone Is Carrier-Locked Before Traveling Abroad in 2026 (iOS & Android)

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Carrier Lock vs. eSIM Compatibility: Why Your 2026 Travel Plans Depend on Both

A common trap for international travelers is assuming that because a smartphone supports eSIM technology, it is automatically ready to accept any data profile worldwide. This misconception leads to sudden connectivity failures right at the arrival gate. To avoid getting stranded, you must understand the distinction between hardware capability and carrier policy enforcement.

`` ┌─────────────────────────────────────────────────────────────┐ │ YOUR SMARTPHONE │ │ │ │ ┌─────────────────────────┐ ┌─────────────────────────┐ │ │ │ Hardware Capability │ │ Carrier Policy │ │ │ │ (eUICC Chip) │ │ (Software Lock) │ │ │ │ │ │ │ │ │ │ Can it physically host │ │ Does your domestic telco│ │ │ │ digital SIM profiles? │ │ permit third-party │ │ │ │ │ │ network access? │ │ │ └────────────┬────────────┘ └────────────┬────────────┘ │ └───────────────┼─────────────────────────────┼───────────────┘ ▼ ▼ [ eSIM-Compatible: YES ] [ Carrier-Locked: YES ] │ │ └──────────────┬──────────────┘ ▼ RESULT: Activation Failure at Destination Gate ("SIM Not Supported" / Profile Rejected) ``

Hardware Capability: The eUICC Chip

eSIM capability is a permanent hardware feature. Inside modern smartphones—such as the iPhone XS and newer, Google Pixel 3 through 9 series, and Samsung Galaxy S20 through S26 lineups—is an eUICC (Embedded Universal Integrated Circuit Card) chip soldered directly to the logic board.

This microchip allows you to provision, download, and store multiple mobile network profiles digitally over the air without swapping a physical plastic card. If your phone has this chip, your device is eSIM-compatible.

Carrier Locking: Software Policy Restrictions

A carrier lock (or subsidy lock) is a firmware-level restriction implemented by mobile operators such as AT&T, Verizon, T-Mobile, Vodafone, and NTT Docomo. Carriers install this software lock on devices purchased on installment plans, multi-year leases, or subsidized contracts to ensure the hardware cannot connect to rival network frequencies until the financial balance is cleared.

Even if your phone possesses the physical eUICC chip to host an eSIM, a carrier lock instructs the baseband modem to reject any cryptographic profile issued by an unauthorized Mobile Network Operator (MNO) or Mobile Virtual Network Operator (MVNO).

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What Happens When You Scan a Travel eSIM on a Locked Phone?

When you purchase a travel eSIM and attempt to install it on a locked device—either by scanning an SM-DP+ activation QR code or downloading a profile via an app—the modem verifies the carrier signature against its internal security policy. Once it detects a non-approved carrier signature, the installation aborts immediately:

• iOS Devices: Throw a hard stop error: "SIM Not Supported: The SIM from this provider is not supported under the activation policy currently assigned by the activation server." Alternatively, you may see: "Cellular Plan Cannot Be Added."
• Android Devices: Display prompt failures such as: "Carrier Lock: Can't use this SIM. To use this SIM, contact your service provider to unlock your phone," or automatically gray out the "Add Mobile Plan" toggle.

`` [Scan QR / Install Profile] │ ▼ [Check eUICC Chip] ────► (No Chip) ────► Error: Device Incompatible │ (Pass) ▼ [Validate Carrier Lock] ──► (Locked) ───► Error: "SIM Not Supported" │ (Unlocked) ▼ [eSIM Successfully Active] ``

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Why Proactive Verification Is Non-Negotiable for 2026 Travel

Relying on airport Wi-Fi to sort out a carrier lock upon arrival in a foreign country is high-risk. Modern travel infrastructure requires immediate, dependable cellular access the moment your plane touches down:

1. Biometric & Digital Immigration Clearances: Several international border authorities require digital landing cards and QR passes generated via live apps before customs exit.
2. Transportation & Safety: Ride-hailing platforms like Uber, Grab, and Bolt require instant authentication codes sent via secure networks.
3. Financial Transactions: Contactless platforms (Apple Pay, Google Wallet) often need background handshakes with financial servers for overseas authorization.

Once your carrier unlocks your device, you can leverage cost-effective international data services like MollySIM. With a properly unlocked phone, installing a digital profile before you fly ensures instant connection upon landing.

``` Standard Travel eSIM (128kbps Throttle): [High-Speed Bucket Exhausted] ──► 128kbps ──► Navigation Buffers / Digital Wallets Fail

MollySIM (384kbps Enhanced FUP): [High-Speed Bucket Exhausted] ──► 384kbps ──► Turn-by-Turn GPS & Apple Pay Remain Functional ```

Unlike basic roaming services that throttle down to a non-functional 128kbps when limits are reached, premium options like MollySIM maintain a 384kbps Fair Use Policy (FUP) fallback speed—three times faster than the standard competitor throttle. This provides enough headroom to keep Google Maps navigation, messaging apps, and authentication tokens running reliably even under heavy use.

Verifying your carrier status well before your travel date prevents avoidable locked-modem errors and keeps your primary digital tools functioning everywhere you go.

How to Check Carrier Lock Status on iPhone (iOS 14 to iOS 19+)

Apple streamlined the carrier verification process by integrating a direct hardware status read-out directly into the iOS settings menu. Rather than relying on trial-and-error with physical SIM cards, you can confirm whether your device's baseband modem is restricted to a single network operator in under ten seconds.

Step-by-Step Settings Navigation

1. Unlock your iPhone and open the native Settings app.
2. Tap General, then select About.
3. Scroll down past your Model Name, Model Number, and Serial Number until you locate the field labeled Carrier Lock (in the UK, Europe, and select international regions, this is labeled Network Provider Lock).

`` Settings ──► General ──► About ──► Carrier Lock ├── "No SIM restrictions" (Ready for International Travel) └── "SIM locked" (Must contact carrier) ``

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Understanding Critical Edge Cases on Apple Devices

Even if your iPhone appears eligible for international use, several hardware and policy edge cases can disrupt connectivity abroad:

1. Dual-SIM Modem Restrictions (IMEI 1 vs. IMEI 2)

On Dual-SIM iPhones (including models with one physical SIM + one eSIM, or dual-active eSIM configurations like the US iPhone 14, 15, and 16 series), carrier locking applies to the entire modem hardware. You cannot bypass a primary carrier lock on IMEI 1 by attempting to install a secondary travel eSIM on IMEI 2. If the field reads SIM locked, both physical and digital slots are restricted to your primary carrier’s network profiles.

2. Enterprise MDM and Configuration Profiles

Corporate-issued iPhones may display No SIM restrictions under the hardware profile while simultaneously blocking unauthorized network modifications via Mobile Device Management (MDM).

• Navigate to Settings > General > VPN & Device Management.
• If an MDM profile is installed, enterprise administrators may have enabled restrictions that prevent the installation of non-whitelisted cellular profiles or restrict international roaming data handshakes.

3. US Reseller Flex Activation Policy

If you purchased an iPhone outright from a third-party retailer (such as Best Buy or Target) rather than directly from Apple, the device may be subject to the US Reseller Flex Policy. These devices appear unlocked in the box but lock to the carrier of the very first SIM card inserted upon initial activation. If you activated the device on an installment plan or MVNO, you must complete that provider’s unlock requirements before it updates to No SIM restrictions.

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What Happens When You Scan a Travel eSIM on a Locked iPhone?

If your iPhone is carrier-locked and you attempt to scan an international eSIM QR code, iOS will initiate the Local Profile Assistant (LPA) handshake, ping the activation policy server, and fail with one of the following system dialogs:

"Unable to Complete Cellular Plan Change" Cellular plans from this carrier cannot be added. This device can only be used with cellular plans from your current carrier.

`` Scan eSIM QR Code ──► iOS LPA Requests Profile ──► GSX Policy Check: "SIM locked" ──► Error: "Unable to Complete Cellular Plan Change" ``

To avoid this failure at your departure gate, verify that your device shows No SIM restrictions well in advance. Once confirmed, installing a MollySIM eSIM profile takes under two minutes. Furthermore, MollySIM's 384kbps Fair Use Policy (FUP) fallback speed ensures that even if you burn through your primary high-speed data tier while abroad, essential services like Apple Pay server authentications, iMessage, and Apple Maps turn-by-turn navigation continue running reliably without stalling.

Checking Network Lock Status on Android Devices (Samsung Galaxy, Google Pixel, & Motorola)

Unlike Apple’s unified iOS interface, the Android ecosystem distributes carrier lock settings across custom OEM skins (Samsung One UI, Google Pixel UI, Motorola My UX). Depending on your manufacturer, carrier-lock statuses reside in different sub-menus.

Follow the OEM-specific navigation paths below to confirm whether your hardware accepts foreign carriers and travel eSIMs.

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1. Samsung Galaxy Devices (One UI 5, 6, & 7)

Samsung integrates dedicated network lock sub-menus within its connection architecture on modern Galaxy S, Z, and A-series models:

1. Open Settings and tap Connections.
2. Scroll down and select More connection settings.
3. Tap Network unlock (on carrier-branded firmware, this may appear as Carrier unlock or Device unlock).
4. Verify the status. An unrestricted device displays:

• Network status: Unlocked (or Permanent Unlock under active status).

`` Settings ──► Connections ──► More connection settings ──► Network unlock ──► "Unlocked" ``

Note: If your menu lacks the "Network unlock" option, navigate to Settings > About phone > Status information > SIM card status. If the field shows your domestic carrier without an option to configure secondary networks, your firmware is locked to that carrier's master PLMN (Public Land Mobile Network).

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2. Google Pixel Devices (Pixel 6 through Pixel 9 Series)

Pixel phones running stock Android interface directly with the Local Profile Assistant (LPA) via the network stack:

1. Open Settings and tap Network & internet.
2. Tap SIMs (or the + icon next to SIMs).
3. Look for the option "Download a SIM instead?" or "Connect to a mobile network".
4. If you tap the + icon and the device immediately launches the camera scanner for a QR code without a restriction warning, your device’s eSIM chip is unlocked.
5. Alternatively, navigate to Settings > About phone > SIM status and confirm the device does not limit slots to a single carrier profile.

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3. Motorola and Vanilla Android Interfaces (Sony, Nothing, Asus)

Motorola and devices running vanilla Android builds store lock flags inside the system hardware status logs:

1. Open Settings > About phone (or System > About phone).
2. Tap Status information > SIM status.
3. Locate the Mobile Network State or Network Lock line.
4. On fully unlocked hardware, this field indicates Unlocked, or allows you to add an APN freely without restriction toggles greyed out.

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4. Advanced Check: Diagnostic Dialer Codes

For devices with open engineering dialers (predominantly unbranded or international Samsung and older Android models), you can query the hardware lock matrix directly using the dialer code:

1. Open your default Phone app dialer.
2. Enter *#7465625#* (mnemonic: #SIMBLOK#) or *#06#** (to check multi-eSIM/IMEI status).
3. If the diagnostic screen launches, verify that every lock parameter reads OFF:

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5. The Definitive Cross-Carrier Physical SIM Test

If OEM settings remain ambiguous, perform a cross-carrier hardware swap:

1. Power off your Android device.
2. Eject the SIM tray and insert an active SIM card from a competing carrier network (e.g., insert a T-Mobile SIM into a device originally financed through Verizon or AT&T).
3. Power the device on.

`` Cross-Carrier SIM Inserted ──► Boot Device ──► Look for: "SIM Network Unlock PIN" ``

• If Carrier-Locked: The screen instantly intercepts the boot sequence with a prompt: "SIM network unlock PIN", "Network locked SIM card inserted", or "Invalid SIM".
• If Carrier-Unlocked: The phone connects directly to the new network, showing active reception bars and the carrier's name in the status shade.

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Ready for International Travel?

Once your Android device is verified as carrier-unlocked, you can download an international travel profile from MollySIM within minutes.

MollySIM data plans feature a built-in 384kbps Fair Use Policy (FUP) speed floor—nearly triple the legacy 128kbps throttle offered by standard travel providers. This continuous baseline bandwidth guarantees that Android essentials like Google Maps live rerouting, WhatsApp VoIP, and contactless Google Wallet token authentications remain fully operational abroad, even after exhausting your primary high-speed data allocation.

Carrier Unlock Eligibility & Policies: AT&T, Verizon, T-Mobile, and Global Telcos Compared

If your diagnostics indicate that your smartphone is locked, you must meet your carrier's specific legal and contractual eligibility criteria before their automated billing system or support desk will process an unlock command.

Unlocking criteria differ significantly between mobile network operators (MNOs). While some carriers execute automated over-the-air (OTA) unlocks after a mandatory holding period, others require manual portal submissions and full settlement of hardware installment agreements.

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Comprehensive Carrier Unlock Policy Comparison (2026)

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Deep-Dive: Specific Carrier Unlocking Rules

1. Verizon Wireless

Under the FCC agreement terms tied to the C-Block 700MHz spectrum purchase, Verizon automatically unlocks both postpaid and prepaid smartphones 60 days after activation.

• Key Detail: The device will automatically unlock even if you still have an active monthly hardware financing balance, provided the account is in good standing and not flagged for fraud.

2. AT&T Mobility

AT&T maintains the strictest hardware unlocking criteria among US tier-1 providers:

• Your device must be active on AT&T service for a minimum of 60 consecutive days (Postpaid) or 6 continuous months (AT&T Prepaid).
• Any associated installment balance, Next Up trade-in contract, or early termination balance must be paid off in full before submitting a request.
• If you recently paid off your device, wait at least 48 to 72 hours for the billing ledger to sync with the IMEI provisioning database before initiating the unlock portal process.

3. T-Mobile US

• Postpaid devices require at least 40 days of active service on the registering line.
• Equipment Installment Plans (EIP) must be paid in full.
• Temporary Travel Unlock (Android Only): T-Mobile offers a temporary 30-day unlock directly via Settings > Connections > More Connection Settings > Network Unlock on select Android devices—useful if you are mid-contract and need to use a travel eSIM temporarily.

4. International Networks (UK, EU, Japan)

• UK/Europe: Regulations by Ofcom and the EU prohibit networks from selling locked handsets. Handsets purchased after December 2026 are unlocked out of the box. Legacy devices can be cleared instantly via your provider's self-care app.
• Japan (Docomo, au, SoftBank): Regulated under MIC guidelines. Handsets purchased outright are unlocked at point-of-sale; financed units require either identity verification or 100 days of active billing history before an unlock token is granted through web portals.

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Step-by-Step: Submitting an Online Carrier Unlock Request

Before initiating international travel, clear your hardware across carrier databases by following these steps:

`` Gather IMEI (*#06#) ──► Check Account Balance ──► Submit Carrier Unlock Form ──► Confirm Email within 24h ``

1. Retrieve Device Identifiers: Open your phone dialer, enter *#06#, and copy the 15-digit primary IMEI (and IMEI2 if using a Dual SIM setup).
2. Clear Pending Ledgers: Settle any outstanding service balances on your telecom account.
3. Access the Official Unlock Portal:

• AT&T: Navigate to att.com/deviceunlock, select "Unlock your device", enter your IMEI, and submit. Check your inbox and click the validation link within 24 hours.
• T-Mobile: On iOS, call 611 or request unlock via T-Life / 24/7 Chat. On Android, navigate to Settings > Connections > Network Unlock and select "Permanent Unlock".
• Verizon: If 60 days have passed and your device displays lock restrictions, dial *611 or contact Tier-2 Global Support to re-push the OTA activation ticket.

1. Complete the Network Handshake: Once your carrier confirms the unlock via email, connect your smartphone to an active Wi-Fi network or perform a standard device reboot to download the updated Carrier Bundle payload.

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Ready for Unrestricted Global Connectivity

After your carrier processes the unlock and your baseband firmware displays No SIM restrictions (iOS) or Unlocked (Android), your smartphone is fully equipped to accept high-speed international profiles.

By eliminating carrier roaming fees and transitioning to a digital travel profile from MollySIM, you gain access to multi-network coverage worldwide. Unlike conventional travel eSIMs that drop down to a sluggish 128kbps speed limit once you exceed your daily quota, MollySIM integrates a robust 384kbps Fair Use Policy (FUP) floor. This 3x speed advantage guarantees that mission-critical travel applications—including Apple Maps, Google Pay contactless validation, Uber ride hailing, and end-to-end encrypted messaging—continue operating smoothly without interruption abroad.

Pre-Trip Troubleshooting: What to Do If Your Phone Is Locked Right Before Departure

Discovering that your smartphone is locked 24 to 48 hours before an international flight triggers immediate logistical friction. If your device displays carrier restrictions right on the verge of departure, standard automated unlock requests may not clear in time due to backend batch-processing cycles.

To prevent connectivity blackouts upon landing, execute these targeted emergency workarounds to expedite carrier intervention or deploy resilient fallback hardware.

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1. Fast-Track Carrier Unlocks via Tier-2 Technical Escalations

Automated web forms on carrier portals often funnel requests into asynchronous queues that take 48 to 72 hours. When operating under extreme time constraints, bypass Tier-1 automated bots and request immediate escalation:

• Demand Tier-2 Tech Support: Dial your carrier's customer service number (611 on domestic networks) and immediately ask for Tier-2 Technical Support or the International Roaming Escalations Desk.
• Leverage Documented Proof of Travel: State clearly that you have scheduled departure ticketing within 24 hours. Tier-2 supervisors have direct access to manual IMEI whitelisting tools and can bypass standard holding periods to push an immediate over-the-air (OTA) unlock payload.
• Request an International Exception: If your account is in good standing but has not met a minor tenure requirement (e.g., 50 days active on a 60-day requirement), supervisors possess the authority to execute an "International Travel Exception Override."

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2. Settling Installment Balances: Overcoming Clearinghouse Sync Lags

Paying off your remaining Equipment Installment Plan (EIP) does not instantly unlock your device. While the financial transaction clears within seconds, the carrier's billing database must sync with their equipment registry and push an updated status to Apple’s GSMA activation servers or Android baseband clearinghouses.

Crucial Warning regarding Weekend Processing: Carrier backend servers regularly schedule database maintenance between Friday night (11:00 PM EST) and Sunday morning. If you pay off a device on a Saturday morning, the unlock ticket may stall until Monday. Always demand that the phone representative confirms the payoff status directly in the carrier’s internal equipment database while you are on the line.

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3. Zero-Hour Fallback Strategies: Backup Devices & Travel Hotspots

If your carrier refuses an immediate unlock or backend clearing delays persist beyond your boarding time, do not rely on standard carrier daily roaming passes ($10–$15/day plus domestic usage limits). Deploy these two proven fallback setups:

`` [ Primary Locked Phone ] │ (Wi-Fi Tether) ▼ [ Unlocked Secondary Device / Pocket Router ] ───► [ High-Speed Local Cellular Network ] ▲ │ (eSIM Data Profile) [ MollySIM 384kbps FUP Engine ] ``

1. The Secondary Unlocked Device Setup: Dust off an older, unlocked smartphone (e.g., iPhone 11 or newer, Google Pixel 4a+, Samsung Galaxy S20+). Install a dedicated travel profile from MollySIM directly onto the secondary device before you board. Once you land, turn on the secondary phone's Personal Hotspot (Wi-Fi Sharing) and connect your primary locked phone.
2. Dedicated Travel Wi-Fi Hotspot / Pocket Router: If you own an unlocked portable LTE/5G pocket router (such as a Netgear Nighthawk or GlocalMe unit), load an international data profile to generate a private encrypted Wi-Fi network for your locked primary handset and laptop.

By routing connectivity through a secondary device powered by MollySIM, your locked phone continues sending iMessages, executing WhatsApp calls, and handling authenticated bank logins over secure Wi-Fi. Furthermore, MollySIM’s built-in 384kbps Fair Use Policy (FUP) speed floor ensures that even after high-speed limits are reached, the tethered connection remains 3x faster than the 128kbps throttled speeds of legacy providers. This critical bandwidth buffer keeps mission-critical utilities—like dynamic turn-by-turn navigation in Google Maps and contactless authentication via Apple Pay—functioning seamlessly throughout your trip.

Seamless Global Setup: Pairing Your Unlocked Device with MollySIM for Instant Connectivity

Once your handset officially displays "No SIM restrictions" or returns an unlocked status from your carrier, your device is ready for dynamic eSIM provisioning. Bypassing predatory international roaming passes and eliminating chaotic airport SIM card kiosks starts with setting up your digital travel profile before reaching your departure gate.

By pairing an unlocked smartphone with MollySIM, travelers access Tier-1 cellular infrastructure across 150+ countries without swapping physical plastic cards or risking line deactivation.

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Step-by-Step Pre-Flight Provisioning Workflow

Setting up your travel profile prior to takeoff ensures your smartphone latches onto local cellular towers the second your plane touches down.

`` [ Verify Unlock Status ] ──► [ Scan MollySIM QR Code ] ──► [ Label Travel Line ] ──► [ Enable Roaming on Touchdown ] ``

1. Verify Base Compatibility: Visit MollySIM and utilize the automated device compatibility lookup tool to confirm your model's regional frequency bands (e.g., Sub-6 5G bands n77/n78 for Europe and Asia, or mmWave/n41 for North America).
2. Select Destination Data Architecture: Choose between country-specific high-speed bundles or multi-country regional passes (such as Europe 39-Country or Asia-Pacific 18-Country packages).
3. Frictionless QR Code Installation:

• On iOS: Navigate to Settings > Cellular > Add eSIM > Use QR Code. Scan the secure installation code sent directly to your email.
• On Android: Navigate to Settings > Network & internet > SIMs > Add SIM (or Download an eSIM) and scan the QR code.

1. Label Your Cellular Profiles: Name the newly downloaded profile "MollySIM Travel" and retain your primary home SIM as "Primary / Personal".
2. Configure Voice and Data Routing: Keep your primary line set for default Voice/SMS (to receive two-factor SMS bank codes over Wi-Fi calling), while assigning Cellular Data exclusively to your MollySIM profile. Toggle Data Roaming to ON under the MollySIM profile settings.

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Technical Advantages of Pre-Boarding Deployment

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Zero-Friction Transit Security

Landing at intermediate transit hubs (such as Hamad International, Singapore Changi, or Frankfurt Airport) frequently results in authentication timeouts when attempting to connect to congested public airport Wi-Fi.

Pre-installing a profile from MollySIM eliminates these vulnerabilities. Your unlocked device immediately acquires local data channels to execute urgent logistics:

• Real-Time Ride-Hailing: Hail Uber, Grab, or Bolt drivers directly from the arrival curb without searching for currency exchange booths or public Wi-Fi access.
• Continuous Safety Margins: Even if high-speed data allotments are depleted during heavy navigation, MollySIM's 384kbps Fair Use Policy (FUP) speed floor remains active. Operating at 3x the speed of legacy 128kbps throttles, this baseline reliably powers critical travel functions—including dynamic vector rendering on Google Maps, contactless Apple Pay / Google Wallet transactions, and end-to-end encrypted messaging via WhatsApp and Signal.