How to Avoid Roaming Charges in Reunion (2026)

With dual SIM, you need to disable roaming on your home SIM specifically. On iPhone: Settings > Cellular > select your home SIM line > Data Roaming (off). Then set the eSIM as your primary data line under Cellular Data. On Android: Settings > SIM Manager > select home SIM > Data Roaming (off). The eSIM stays set to allow data. This prevents AT&T from charging $10/day while your Reunion eSIM handles data through Orange RE. Both SIM lines stay active: home SIM for calls and texts, eSIM for data at $3.67 instead of carrier roaming rates.

Yes, background apps are one of the most common sources of surprise roaming bills. With data roaming enabled and no day pass, AT&T charges $2.05/MB in Reunion. Background App Refresh on iPhone syncs mail, news, and social apps every 15-30 minutes automatically, including at 3am while you sleep. A single overnight background sync session can accumulate $50-200 in charges without you opening your phone. Disable Background App Refresh before travel: Settings > General > Background App Refresh > Off. Then disable data roaming. An eSIM replaces carrier data entirely. Background syncs bill against the eSIM's flat-rate data at $3.67, not your home carrier's per-MB rate.

On iPhone: Settings > Cellular > scroll down to "Current Period Roaming" to see total roaming data consumed. On Android: Settings > Connections > Data Usage > Mobile Data Usage > select your SIM, then filter by roaming. Check this immediately after landing in Reunion to catch charges early. AT&T also sends usage alerts at 50%, 75%, and 100% of Day Pass data limits. Log into the myAT&T or My Verizon app for itemized charges from Orange RE. If roaming data appeared, enable Airplane Mode, disable data roaming, and call your carrier within 48 hours. Prevent future charges with an eSIM at $3.67 for 1GB.

Yes. An eSIM connects to Orange RE, the same network infrastructure AT&T and Verizon use for roaming in Reunion. You get identical towers, identical coverage area, and the same 5G speeds. The only difference is billing: your carrier charges $10/day or $2.05/MB for roaming access to these towers, while the eSIM charges $1.83/GB for the same connection. There is no coverage penalty for using an eSIM. In many cases, eSIM data speeds are faster because carrier roaming agreements sometimes throttle international users to lower priority.

AT&T and Verizon charge Day Pass fees per line, not per account. A family of four on AT&T Day Pass pays $40/day in Reunion, totaling $280 for a 7-day trip. Children's phones are particularly risky because apps and games download updates in the background. One child's iPad streaming a YouTube video at $2.05/MB racks up $400+ in under an hour. Four eSIMs on Orange RE cost roughly $21.92 total for 3 GB each. Share one eSIM's hotspot to cover all devices and cut costs further.

Use both. WiFi Calling routes calls through your home carrier over WiFi, using your home minutes. It is free on most US carrier plans. The limitation: WiFi Calling only works when connected to WiFi, not mobile data. An eSIM on Orange RE at $3.67 gives you mobile data everywhere. Use WhatsApp or FaceTime over eSIM data for calls when WiFi is unavailable. Enable WiFi Calling before departure: iPhone Settings > Phone > WiFi Calling. When on hotel WiFi, calls route free through your home carrier. When on mobile data, use WhatsApp calls through the eSIM.

Your home number stays fully active. With dual-SIM setup, your home SIM keeps your phone number for calls and texts while the Reunion eSIM handles data on Orange RE. You receive calls on your home number. SMS messages arrive normally. Data routes through the eSIM at $3.67 instead of your carrier's $10/day roaming. On iPhone, set Cellular Data to the eSIM line and Default Voice to your home SIM. Both lines work simultaneously. Your home number is not affected by the eSIM installation and remains active throughout your entire trip.

Most travel eSIMs for Reunion connect to Orange RE and SFR as the primary network, with automatic fallback to secondary carriers if the primary signal is weak. Your phone selects the strongest available tower. This multi-carrier support means better coverage than a single-network physical SIM. When roaming with AT&T or Verizon, you are locked to their specific roaming partner. The eSIM's ability to connect to multiple Reunion carriers provides wider coverage at $3.67/GB versus $10/day for limited carrier roaming.

Complete setup before departure: (1) Disable Data Roaming on iPhone: Settings > Cellular > Data Roaming (off); Android: Settings > Connections > Mobile Networks > Data Roaming (off). (2) Turn on Airplane Mode before landing to block automatic carrier attachment to Orange RE. (3) Activate your pre-installed eSIM on local WiFi or after landing. (4) Set your home SIM to calls-only or data-off. Your home number stays active for calls and SMS; the eSIM handles all data without triggering your carrier's $10/day roaming rate.

For a single day in Reunion, AT&T Day Pass at $10 is comparable to a basic eSIM. However, the Day Pass auto-activates from a push notification and you cannot control the start time. If your flight lands at 11pm and a notification triggers the pass, you pay $10 for one hour of the first day, then another $10 the next morning. An eSIM at $3.67 for 1 GB covers the entire layover with no auto-activation risk. For layovers over 6 hours, the eSIM wins. For 2-hour layovers where you stay on airport WiFi, neither is necessary.

Yes. Carrier signals do not stop at the political border. Your phone detects Orange RE's towers up to 5-10 miles before you physically cross into Reunion. If Orange RE's signal is stronger than your home carrier's at that point, your phone may attach and roaming charges begin before you cross. This is common near busy border crossings where carriers position towers to capture cross-border traffic. Turn on Airplane Mode at least 10 miles before the border. Disable data roaming in Settings before re-enabling cellular. Install an eSIM at $3.67 to prevent automatic carrier attachment entirely.

The safest approach: enable Airplane Mode before the ship leaves any port near Reunion. Then manually re-enable WiFi only (Airplane Mode stays on, just WiFi toggled back). This disconnects from all cellular networks including maritime satellite, while keeping ship internet access. On iPhone, swipe to Control Center, tap Airplane Mode (orange icon), then tap the WiFi icon to re-enable it. On Android, the same approach works through Quick Settings. Verify your cellular status: no carrier name or bars should appear in the status bar. When your port stop arrives, disable Airplane Mode and your eSIM at $3.67 connects to Orange RE on the Reunion shore network.

Offline maps eliminate the largest single source of navigation data use. Google Maps online navigation in Reunion consumes 5-10 MB/hour of active use. Downloaded offline maps reduce that to near zero for turn-by-turn directions. Download your Reunion region before departure over home WiFi: Google Maps app > search for Reunion > three dots > Download Offline Map. Apple Maps also supports offline downloads in iOS 17+. A typical Reunion offline map is 100-500 MB and covers the entire country for navigation. This saves 100-500 MB over a 7-day trip on Orange RE, reducing how much of your eSIM plan at $3.67 you consume on maps alone.

Yes. Your phone does not need to be in your hand to trigger roaming charges in Reunion. Background processes sync email, update weather, refresh social feeds, and ping location services automatically through Orange RE. AT&T International Day Pass activates the moment any data crosses the connection, even a single push notification received while your phone sits in your pocket. That costs $10 for the calendar day. Disable data roaming before landing: Settings > Cellular > Data Roaming (off). Without this step, your phone generates charges from Orange RE without you touching it. An eSIM at $3.67 handles all background syncs at flat-rate pricing.