expo-device-country

Expo module that exposes the device's ISO 3166-1 alpha-2 country code using SIM and network data where available. Ideal for tailoring content or flows by a user's detected country without asking for additional permissions.

iOS note: Apple does not expose an API for the currently registered network country, so getNetworkCountry() always returns null on iOS. Only SIM/home carrier data is available there.

New Architecture: Fully compatible with Expo's New Architecture out of the box.

Features

• Synchronous helpers to read the SIM-issued country code as a two-letter ISO string, e.g. US or TH.
• On Android, access to both the SIM country (TelephonyManager.getSimCountryIso) and currently registered network country (TelephonyManager.getNetworkCountryIso).
• Designed for Expo Router/React Navigation and other client-side flows that need country awareness without server round-trips.
• Seamless autolinking in Expo apps and React Native projects configured with Expo modules.

Installation

Expo app projects

npx expo install expo-device-country

This works for Expo projects created with npx create-expo-app, including apps built with EAS or classic builds.

React Native projects (with Expo modules)

npm install expo-device-country
# or
# yarn add expo-device-country
# pnpm add expo-device-country

npx pod-install

Make sure the expo package is configured by following Install Expo modules in React Native projects.

Usage

import ExpoDeviceCountry from "expo-device-country";

const simCountry = ExpoDeviceCountry.getSimCountry();
const networkCountry = ExpoDeviceCountry.getNetworkCountry();

if (simCountry) {
  console.log(`SIM country: ${simCountry}`);
}

// Fall back to network country when SIM data is unavailable
const resolvedCountry = simCountry ?? networkCountry ?? "US";

Both methods return a two-letter uppercase country code or null if that dataset is not available on the device.

API

| Method | Description | Return type | Platforms | | --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------- | ------------------------------------------ | | getSimCountry() | Reads the home carrier/SIM country. On iOS this uses CoreTelephony; on Android it uses TelephonyManager#getSimCountryIso. No additional permissions required. | string \| null | iOS: available (SIM only); Android: available | | getNetworkCountry() | Reads the currently registered mobile network country. Returns null on devices without cellular service or on iOS, where the data is unavailable. | string \| null | iOS: not available; Android: available |

Note: Web support is not available. The module can only be imported on native platforms.

Example app

The example/ directory contains a minimal Expo app that consumes this module.

cd example
npx expo start

Platform notes

• iOS: getSimCountry uses CTTelephonyNetworkInfo and returns null on Wi-Fi only devices or when no SIM is present. getNetworkCountry always returns null because iOS does not provide this information.
• Android: Uses TelephonyManager to resolve SIM and network countries. A value is only returned on real devices with an active SIM or network registration.

License

MIT