Paris sends two very different long-haul evenings across the Atlantic, and a phone treats them as one problem. Mexico City and Cancún sit about eleven to twelve hours away; São Paulo and Rio de Janeiro are a similar stretch. Everything the handset needs is settled before boarding: find out what your own contract does past Europe, pay for the destination plan while you are still in France, load it on home Wi-Fi, and keep it switched off until immigration has finished with you. Visiting both countries means buying twice.
Where the European rules stop
Inside Europe a French line mostly forgets it has left home, and a couple of holidays in Spain or Portugal are enough for its owner to forget too. The forgetting is the part that costs money. Those rules have an edge, Mexico and Brazil lie well past it, and past it the terms governing your line come out of your own contract and nowhere else.
Ten minutes with that contract, a week out, is the whole job. Look for the clause covering the rest of the world, then read what it sets out for data, for voice, and for the background traffic a handset produces on its own. Most people finish reading and land on the same split: the French line keeps the number, and travel data comes from something bought for the country in question.
Before the gate, not at it
Pay and install several days ahead, sitting down. Long-haul days out of France rarely start at the gate — a TGV into Roissy, an early hop up from Lyon, Marseille or Nice, the transfer between Orly and Charles de Gaulle — so by boarding you have been awake and moving for a long time. Terminal Wi-Fi will open a message; it is a bad place to attempt a first profile download.
Three jobs belong to the kitchen table. Store the order confirmation and the installation code on something other than the handset carrying the profile. Save the first address in each country, the name of whoever is collecting you and the booking reference into a note that opens with nothing behind it. And find the sentence about when the clock starts, because offers do not agree on which event opens the window.
Landing in Mexico
Being on the ground is not being through. Passport control, then the belt, then whatever transfer your airport imposes: a handset changes none of it, so leave the travel profile asleep until you are outside with your bags.
At that point the settings take a minute. Switch the Mexican profile on and give it the data roaming permission, which is what lets a visiting profile register on a local network; it applies to the profile you enabled and to nothing else. Point mobile data at it. Your French line stays live for calls and messages, but its own mobile data comes off, so nothing there quietly reaches for a network.
Then the geography takes over. At Benito Juárez the pickup arrangements differ between the two terminals, and the link running between them is not the transfer into the city. Cancún separates into three pins as well — where you land, the hotel strip, and the address itself — and the meeting point normally sits in the last message a driver sent rather than in the booking.
Landing in Brazil
Brazil rearranges the same three questions. Rio's international traffic arrives at Galeão, a good twenty kilometres from Copacabana; Santos Dumont, two kilometres or so from the centre, is where most domestic legs leave from, which means a Rio stay can quietly include a change of airport. São Paulo's long-haul flights land at Guarulhos, well out of town, and the road in is a stage of the journey, not a detail at the end of it.
Then you start typing. A driver at the kerb will describe in Portuguese which side of the building he has pulled up on and expect a reply within the minute. Whichever messaging application you already use is the one carrying that exchange, so sign into it and test it in France.
What the two trips demand
Mexico charges the phone for movement. Its regions are joined by flights rather than roads, so a two-region itinerary arrives twice, and the stretch of coast below Cancún is a relay of separate bookings — a car, a bus or train leg, a boat, one final collection — each with its own company and its own written arrangement. Sit on one beach for a week and almost none of that applies, until the weather rewrites an afternoon.
Brazil charges it for distance. Salvador lies some 1,650 kilometres up the coast, Foz do Iguaçu roughly 1,100 inland, and neither is a drive; the six-hour bus along the 430-kilometre corridor to São Paulo is the exception people actually take. Rio's days go upward as well as along: the climb up Corcovado and the ride to the top of Sugarloaf both put you above the city rather than in it, and their ticket times are better read early.
Two countries, two purchases
Nothing on the shelf here bundles Latin America. At the time of writing the regional listings named regions elsewhere and nothing covering this one, which makes a two-country route a Mexican purchase and a Brazilian purchase, arriving as two profiles with two allowances and two expiry dates. The second does not extend the first.
Sizing belongs to the two longer guides. Choosing well in Mexico turns on the gap between the Yucatán and the high interior; the Brazilian version turns on a language most visitors read better than they speak. Compressed to a line: a normal fortnight in either country points at something near ten gigabytes, and the day count deserves more thought than the allowance does, since a window that runs out before the return flight is the expensive kind of mistake.
Current sizes and windows live on the Mexican listings and the Brazilian ones, each printing the exact territory its offers name. Carrying on below Mexico means buying country by country, which is what the directory for that stretch of map is for.
Keeping the French number
Data is all the travel profile does, and that is deliberate. The number you have always used stays on the line it came in on, still ringing, still taking text messages, still taking whatever code a French bank sends when a card appears abroad. What those calls and texts cost outside Europe is, once again, a question for your contract.
Tip: A French card used at a counter in Guadalajara or a kiosk in Salvador often triggers a confirmation step, and the bank sends it to the number on its file. Install the bank's own application and confirm that the number on file is the French one still in the phone. A card reader that has already refused you is a poor place to find out.
A Mexican or Brazilian number is a different product altogether, and a data-only line does not include one, although the messaging applications everybody uses run perfectly well on it. Where the selected plan supports a top up, the additional allowance attaches to the profile already sitting on the handset. On the way home the order reverses: mobile data returns to the French line, and both travel profiles stay installed.
Short answers
Does my French contract work in Mexico and Brazil? On whatever terms it sets for the rest of the world. Nothing else answers it, so look before you book.
How long are the flights? About eleven to twelve hours nonstop to Mexico City or São Paulo, and not far off that for Cancún or Rio de Janeiro.
Can one plan cover both countries? Not here. They are two country plans, so a route taking in both is two purchases and two windows.
When should the second profile come up? Once you are out of the hall with your bags, not while you are queuing.
Do I keep my French number? Yes. It stays on its own line, the bank codes still reach it, and only the data moves.
