Best eSIM Argentina: Six Plans, Four Trip Lengths, One Reversal

Every Argentina eSIM comparison published in English says a version of the same sentence: a travel plan is cheaper than buying locally, and here are the gigabytes. That sentence is true in Iceland, in Japan, in Norway. In Argentina it is the opposite of true, and the reason is a single number that the same articles keep quoting without reading.

Argentina sells mobile data at about $1.11 a gigabyte. Cable.co.uk’s survey of 237 markets puts the country 104th cheapest, comfortably below a global average of $2.59, and roughly a quarter of what a gigabyte costs in the United States. The cheapest travel plan that will sell you a gigabyte to use in Buenos Aires charges $1.76. So the premise of the entire category — buy before you fly, it is cheaper — is inverted here, and every “best of” list that ranks these plans by price per gigabyte is ranking the wrong thing without noticing.

The short answer, before the tables. For a trip of four days or less, buy a travel plan and stop reading: the money you save on a local chip is smaller than the cost of getting to a shop. For a trip of two weeks or more, the local chip wins on data and loses on time, and which of those you have more of is the actual decision. For the middle — the seven-to-ten-day holiday that most people take — the answer depends on one question almost nobody asks before paying: whether the “unlimited” plan you are looking at is unlimited at all. In Argentina, three of the biggest names in the business sell an unlimited plan that stops being fast after 3 GB in a day.

What follows is the arithmetic behind those three sentences, the six providers that will sell you an Argentine plan, and the four itineraries where the right purchase is different.

Why is Argentina the one country where a travel eSIM loses on price?

Start with the number, because everything else is downstream of it.

Cable.co.uk collects mobile plans market by market and computes what a gigabyte costs, then averages. Argentina’s figure of $1.11 is the outcome of that exercise, and it is not a rounding error: the same survey puts the global mean at $2.59, which means Argentine mobile data is priced at 43% of the world average. Among the 237 markets tracked, that lands the country in the cheapest half of the cheapest quartile — the sort of place where a resident tops up without thinking and a visitor’s assumption that local means expensive quietly fails.

Contrast that with the two markets most US travellers bought an eSIM for in the last three years. Japan’s gigabyte runs several dollars. Norway’s is $4.07, which is nearly four times Argentina’s. In both of those countries a travel plan is genuinely cheaper than a local prepaid, and the habit formed there transfers badly.

The consequence is a price floor that no reseller can get under. A travel eSIM buys wholesale capacity from an Argentine operator and marks it up; if the wholesale gigabyte costs a dollar and the retail gigabyte costs a dollar eleven, there is almost nothing in the middle. So the plans are priced not against Argentina’s data market but against what US and European buyers are used to paying, and they land where a US buyer’s expectations sit — around two to five dollars a gigabyte.

The $1.11 figure is an average, not a shelf price

Here is the part the comparison articles skip, and it is the part that changes the decision.

Cable.co.uk’s number is an average across the plans it sampled, weighted by nothing except being a plan. Big bundles pull it down. A 30-day, 20 GB resident plan at a low per-gigabyte rate counts exactly as much as a three-day tourist top-up at a high one. So $1.11 is a statement about the shape of the market, not a price tag you can point at.

Two things follow. The first is that no visitor can actually buy a gigabyte for $1.11, because visitors do not buy 30-day resident bundles — they buy the small, short packs that sit above the average. The second is that anyone quoting $1.11 as a reason to skip the eSIM is quoting a number they could not have paid either. The fair version of the comparison is this: the local route’s floor sits somewhere below the travel plans, possibly well below, and the gap narrows to nothing once you buy in tourist-sized quantities.

That reframing matters because it moves the argument off price and onto everything else — the queue, the card, the queue’s opening hours, the currency. Those turn out to be the things that decide it.

Who sells an Argentina eSIM to a US buyer in October 2026?

Six providers matter, and they are not variations on one product. They differ in which local network sits underneath, whether they sell metered data or unlimited, and how long you have between paying and switching on.

The second column is where this market is least competitive, and the pattern is not quite what the price list suggests. Five of the six land on the same network. Airalo, Nomad and Roamless name Movistar; Ubigi names Movistar and Telecom Personal; Holafly names Telefónica, which is the company that owns the Movistar brand rather than a fourth carrier. Saily names nobody. A market that reads like a choice of six operators is a choice of one, with a single exception — and that exception is the network with the best measured speeds in the country. Personal is named by exactly one seller, and that seller names the fallback alongside it.

That single fact changes the recommendation for anyone driving rather than city-hopping, and it is developed properly in the Airalo review for the opposite reason: Airalo’s portfolio is the narrowest of the six.

The fourth column is where the real product differences live, and it is where most buyers get caught. Airalo, Holafly and Roamless sell you a duration with an implicit data ceiling. Nomad, Saily and Ubigi sell you a quantity with an implicit duration. Those are different products with different failure modes, and comparing them on a single “price per gigabyte” line is how people end up with a plan that expires on day nine of a twelve-day trip.

Airalo, Nomad and Roamless all name Movistar. Ubigi names Personal as well.

Argentina runs on three networks: Personal, Claro and Movistar. Ookla’s measurement for the second half of 2025 gave Personal the fastest median download in the country at 55.48 Mbps and the lowest latency at 37 ms, with Claro second at 39.79 Mbps and the better reputation outside the cities. Movistar did not lead on speed anywhere that counts.

That does not make a Movistar-based plan bad. It makes it a plan that lands on the network with the most fallback value and the least speed, which for a city trip is invisible and for a driving trip is the difference between a map and a blank screen. The full network picture — province by province, city by city, including the four-fold spread between Buenos Aires at 113.51 Mbps and Misiones at 27.57 — belongs to the Argentina carrier guide and is not repeated here.

What belongs here is the purchase consequence, and it is the one finding on this page that changes an actual recommendation: if your itinerary leaves the cities, the provider that publishes Personal is worth more than the provider that is cheapest. Ubigi is the only one of the six that names both Movistar and Telecom Personal, with automatic switching between them. For a Patagonia route that is a second network to fall back on, in the one part of the country where a fallback is the difference between a working phone and an expensive camera. It costs about $2.30 a gigabyte against Nomad’s $2.80, so the coverage advantage does not come with a price penalty — which is rare enough to be worth stating twice.

Which metered plan is cheapest per gigabyte at 5 GB and at 20 GB?

Metered plans are the honest end of this market: you pay for a quantity, the quantity is what you get, and the only question is the rate. Here are the four providers that sell them, read on 26 October 2026.

Read down the columns and three things appear that no ranking page mentions.

The first is that Ubigi wins the per-gigabyte race outright and is almost never on a “best of” list. Ten gigabytes for $23 is $2.30 a gigabyte; 25 for $44 is $1.76. Nomad’s comparable tier is $2.80, Saily’s roughly $3.00 in euro terms, Roamless’s $3.00. On a two-week trip using 10 GB, choosing Ubigi over Nomad saves $5; choosing it over Roamless saves $7.

The second is that Nomad’s ladder is not linear, and the 5 GB tier is the trap. Nomad charges $16 for 5 GB, which is $3.20 a gigabyte — more per gigabyte than its own 3 GB tier at $3.17. Paying more for a bigger bundle is the normal direction; paying a worse rate for one is not, and it means the 5 GB tier exists for people who will not do this division.

The third is that Saily quotes in euros to a dollar buyer. At a euro-dollar rate near 1.18, its €14.99 for 5 GB is about $17.70, which is more than Nomad’s $16.00 — the exact reverse of the impression the smaller number gives. There is a whole review of what else that currency choice costs you in the Saily breakdown, but for pricing purposes: convert before comparing, and convert at today’s rate, not last year’s.

The cheapest gigabyte in Argentina starts at 10 GB

So the cheapest Argentina eSIM by the gigabyte is $1.76, from a provider that does not advertise itself as cheap. The most expensive single gigabyte is Ubigi’s own 1 GB tier at $6.00 for a week — the same provider, a different end of its ladder, and a reminder that “cheapest provider” is never a property of a brand.

Note what you have to do to get the $1.76: buy 25 GB. Ubigi does not sell that rate in small quantities, and neither does anyone else. Every provider’s best per-gigabyte figure is attached to the tier almost no short-trip traveller needs, which is why “cheapest per gigabyte” is such a misleading way to shop for a four-day visit — and why the four-day answer later on this page looks nothing like the ten-day one.

Is the unlimited Argentina eSIM capped at 3 GB a day?

Yes — and this is the single most consequential fact in the category, because it is not on the checkout page in the size it deserves.

Airalo’s unlimited Argentina plans, Saily’s unlimited tier and Roamless’s unlimited plans all share one design: a daily high-speed allowance of 3 GB, after which the connection continues but drops to 1 Mbps. That is roughly the speed of a weak 3G signal. Maps load. Messages send. A photo upload takes a while. A video call does not happen, and neither does a two-gigabyte camera-roll backup to the cloud.

So “unlimited” in Argentina means thirty gigabytes of usable data on a ten-day plan, with a slow trickle after it. Once you read it that way, the product stops being a different category from metered data and becomes a metered plan with a soft landing — which makes it directly comparable, and which changes which one is cheapest.

Do the division:

Airalo’s ten-day unlimited lands at $1.28 per usable gigabyte, which undercuts every metered plan in the previous table including Ubigi’s $1.76. That is a genuinely good product and almost nobody frames it that way, because “unlimited” and “cheapest per gigabyte” do not look like they belong in the same sentence.

Saily’s €51.49 is the odd row, and the oddness is the point: the page does not state how many days that price covers. A €51.49 purchase at an unknown duration cannot be compared, only guessed at, and guessing is what the price is designed to invite.

The 180-day window changes what is safe to buy early

One purchase detail deserves its own paragraph because it decides whether any of this is available to you.

Saily allows 180 days between buying and activating; Nomad allows 60; the rest do not publish a figure. If you book flights in January for a June trip and buy your plan in the same week — which is what “buy early” advice tells you to do — Nomad’s plan activates itself in March while you are at work, and the allowance starts running against a trip you have not taken. Saily’s survives that mistake. Airalo’s and Holafly’s behaviour on this point is worth checking in their own help pages rather than trusting a comparison table, mine included.

The practical rule: buy early only from a provider that publishes a window longer than the time between purchase and departure. Otherwise buy in the week before you fly.

Which unlimited plan wins at 7 days and which at 10?

Put the durations side by side at their per-day cost and the shape of the market becomes obvious.

Every figure above is a page price read on 26 October 2026, in the currency each provider quoted to a US visitor. Ladders like these get re-priced mid-quarter without notice, so what is worth trusting is the ordering, not the dollars.

Three conclusions, none of which appears in a listicle.

Airalo owns seven days and ten days. At both lengths it is the cheapest of the three, and at ten days the gap to Roamless is $7.10 — enough to matter on a trip where the flight was bought on points.

Holafly owns day twelve. Not because it is cheap, but because it is the only one of the three with a 15-day and a 30-day product. If your trip is a fortnight, Airalo’s longest unlimited plan expires on day ten, and the choice becomes buy ten days and hope, buy two overlapping plans, or move to Holafly at $50.50. That last one is the only purchase on the page that matches the trip.

Three days is a bad deal everywhere. Every provider on this table charges between $6.36 and $6.69 a day at three days — roughly double what the same product costs per day at ten. A long-weekend trip to Buenos Aires is the single most expensive way to buy unlimited data in Argentina, and it is also the most common trip. That is why the four-day itinerary later on this page is priced differently.

What happens when any plan expires two days before the flight?

This is not a hypothetical. A fortnight is the standard length of an Argentina trip, because the country is 3,700 kilometres long and nobody flies that far to see one city — and ten days is where the ladder ends at the biggest seller in this market. The trap is not the price of the extra days; it is that there are no extra days to buy.

Take the case that produces it most often: twelve days in the country and Airalo’s ten-day unlimited at $38.50, bought because it was the best per-gigabyte product on the market. On day eleven the plan is finished. Your options are:

• Buy a second plan from the same seller. The smallest unlimited is three days at $19.50, which brings the total to $58 for twelve days — more than Holafly’s fifteen-day plan, for three fewer days.
• Buy a metered top-up. Airalo sells top-ups, and a 5 GB one will get you through the last two days for less than a second unlimited plan. This is the correct answer, and it is not on the plan page.
• Do nothing and use Wi-Fi. Genuinely fine for the last two days if they are in Buenos Aires. Genuinely not fine if they are in El Chaltén.

The lesson generalises beyond Airalo: a duration-based plan is a deadline, and the deadline is usually two days before your return flight. Before you pay, count the days from “wheels down” to “wheels up” and compare that number to the longest duration on offer. Not the days you are travelling — the days you are there. The two differ by one, and that one is often the day you need a map most.

What do the fixed costs of a local chip add up to in pesos?

Now the other side of the comparison, and the reason the $1.11 figure does not settle it.

Buying a local chip is not a transaction, it is an errand. It has a fixed cost that does not scale with how much data you buy, and the fixed cost is paid in three currencies: money, time and risk.

Money. A ride from Palermo or Recoleta to a carrier store and back is a few dollars each way in a Cabify or Uber — call it $6 round trip if the store is in a mall rather than on your block. That is the smallest of the three costs and the easiest to count.

Time. Argentine carrier stores run on Argentine hours. A registration is not a two-minute transaction: the assistant enters your passport details, the line clears, and then you can buy a data pack. Budget an hour including the trip, and note that an hour of a four-day trip is 1% of the whole holiday. An hour of a fourteen-day trip is 0.3%.

Risk. This is the cost nobody prices and everybody who has done it remembers. Argentine card terminals decline foreign cards more often than terminals in Chile, Uruguay or Brazil — not universally, not always, but often enough that “bring cash” is standard advice for the country rather than a quirk. A declined card in a queue behind six people, with a data pack you need and no working phone to check your bank’s fraud SMS, is a specific and unpleasant five minutes.

Cabify, a queue and a declined card: costing the detour

Put the three together and the detour has a price: roughly $6 and 60–90 minutes, plus a real chance of a second attempt.

Against that, the saving on data. Even granting the local route the full $1.11 average — the best case it can possibly achieve — the gap to the cheapest travel gigabyte at $1.76 is $0.65 a gigabyte. To pay off a $6 detour, you need to use nine gigabytes. To pay off the hour, at any reasonable valuation of holiday time, you need considerably more.

Which produces the number this page exists to give you:

Under about 5 GB of use, the local chip loses on money as well as time. Between 5 and 15 GB it is a wash decided by how much your first morning is worth. Above 15 GB, the chip wins and no amount of per-gigabyte arithmetic on the eSIM side closes the gap.

Two weeks of normal tourist use — maps, messages, a few hundred photos, no video — sits somewhere around 8 to 12 GB. That is the middle band. It is why “which is cheaper in Argentina” gets a shrug rather than a table, and why “which is better” gets the same answer for almost everyone reading this: a travel plan.

At how many days does the local chip beat every eSIM?

Days are a proxy for gigabytes, and gigabytes are what actually decide it, but days are how people think about their trip. So here is the same conclusion in the unit travellers use.

A light user — navigation, messaging, translation, ride-hailing, photos uploaded over hotel Wi-Fi at night — burns somewhere between 400 MB and 800 MB a day. A normal user who posts photos and watches a little video lands near 1 GB a day. A heavy user tethering a laptop or streaming in the evening passes 2 GB a day and should not read the rest of this section, because they should simply buy the largest metered plan available.

At 1 GB a day:

The crossover sits between ten days and a fortnight, at least on money. On convenience it sits much earlier, and for most people convenience is the variable that actually decides — which is why the recommended purchase for a ten-day holiday is still a travel plan, even though the table shows the local chip ahead on cash from day fourteen.

The one case where the arithmetic stops being close

If you are staying a month, or working remotely from Buenos Aires, everything above inverts. A resident-style 30-day bundle at a per-gigabyte rate near the national average beats any travel product by a factor of two or more, and the detour becomes a rounding error against a month. Every long-stay guide says this. It is the one case where the standard advice is right.

Stays that long tend to grow into trips that cross borders — a month in Buenos Aires followed by Chile and Colombia is a common shape — and that is a different purchase again, priced leg by leg for a 50-day three-country route rather than for a fortnight in one place.

Does a peso top-up make budgeting worse than a dollar checkout?

A peso-denominated plan has a property that is invisible on the price list: it is denominated in a currency that moves.

Argentina’s inflation has been running hot for years and carrier tariffs are re-priced through the year rather than annually. That has two effects on a visitor. The first is that any peso figure you read in an article — including in this one — is a snapshot with a short shelf life, which is why this page quotes measurement benchmarks and dollar prices instead of a tariff sheet. The second is that topping up mid-trip means paying a second time at a rate you did not see coming, in cash, at a kiosk whose exchange rate is not the official one.

That is not a reason to avoid the local route. It is a reason to buy the largest pack you might need in one transaction rather than three, because each additional transaction re-exposes you to the rate and the queue.

A dollar checkout has the opposite property: the price is fixed at purchase, in the currency of your bank account, and nothing that happens to the peso changes it. For a traveller on a budget that is worth something real — not a lot, but more than the $4.55 you would save over a week by going local.

Which plan fits a 14-day Patagonia route with two flights?

Two weeks, Buenos Aires to El Calafate, overland to El Chaltén, back through Bariloche. It is the standard Patagonia itinerary and it stresses a data plan in a specific way: long stretches with no signal at all, punctuated by towns where you want everything at once.

Budget 12 to 15 GB. Buy one plan, not two — the plan-switching failure mode on day eleven in a town with one carrier store is worse than any price difference.

If price is the only variable: Ubigi’s 25 GB at $44, which is $1.76 a gigabyte and lasts 30 days. You will finish the trip with gigabytes to spare and no second purchase.

If duration is the risk: Holafly’s 15-day unlimited at $50.50, the only plan on the market that matches a fortnight without a deadline. Cost per day is $3.37, which is competitive with anything metered at that allowance.

If network fallback matters: this is the one route where the choice is made by the operator list rather than the price list. In Patagonia the bottleneck is the tower, not the brand, and a plan that switches between Movistar and Personal will hold a bar where a single-carrier profile would not. Only Ubigi publishes both, which makes it the answer here even though it is not the cheapest on this page. The regional coverage detail covers which province does what.

What not to do: buy a 5 GB plan for a fortnight. It is the single most common Argentina purchase and it runs out, reliably, on day six — which is usually the day you reach the part of the country where buying more is hardest.

Which plan is right for a 4-day Buenos Aires stopover?

Four days, one city, a hotel with Wi-Fi. This is the trip where the entire category is at its worst value and the advice inverts.

At three or four days, every unlimited plan on the market charges about $6.50 a day. A metered plan at 3 GB costs $9.50 and covers the whole trip if you lean on hotel Wi-Fi in the evening. The 3 GB metered plan is half the price of the cheapest unlimited plan and is the correct purchase for this itinerary — a conclusion that every “unlimited is simpler” recommendation gets wrong for exactly the trips where most people travel.

Use the Wi-Fi. Download the offline map of Buenos Aires, including the Subte, before you land, because the metro has no usable signal on any network and the map will not load underground. Stream nothing. Then 3 GB is generous rather than tight.

What a hotel’s Wi-Fi does to your daily gigabyte count

The variable almost nobody models is that a hotel room absorbs most of your heavy usage. Photo backups, app updates, video, the inevitable two hours of scrolling before sleep — all of it happens on Wi-Fi if the Wi-Fi works. What is left for mobile data is the part of the day you are outside, which is maps, messages, a handful of searches and maybe a video call home.

That is why the same traveller who burns 2 GB a day at home burns 600 MB a day in Buenos Aires, and why “how much data do I need” has no country-level answer. Size the plan around your evenings, not your days.

What does an eSIM do at Ezeiza that a chip cannot?

It works while you are still in the arrivals hall, and in Argentina that turns out to matter more than it should.

Ezeiza’s arrivals area is not a shopping centre. The carrier presence there is thin — historically a single brand’s stand — and a flight that lands at 06:00 or 22:00 finds whatever is there closed or closing. Outside the airport, carrier stores keep shopping-centre hours, which is to say they are shut when a red-eye lands and shut again on Sunday.

An eSIM installed at home has none of those constraints because there is nothing to collect. You install the profile on Wi-Fi before you leave, leave the line switched off, and turn it on when the plane stops. The install sequence takes about five minutes on home broadband and should never be attempted in an arrivals hall, where the Wi-Fi is the one thing you cannot rely on. The profile attaches to a network within a minute or two of the first attempt — longer than later attaches, which is normal and not a fault.

That is worth $4.55 to most people on a week’s trip. It is worth considerably more to anyone landing outside business hours, which is most long-haul arrivals from the US. If the profile will not attach at all, the usual cause is in the troubleshooting walkthrough rather than in the plan.

Which four trips need no Argentina eSIM at all?

Not every trip needs one. The four below are the common ones.

Your carrier includes Argentina. Several US and European postpaid plans now bundle Latin American roaming at usable speeds. Check the roaming terms before you buy anything: if Argentina is included at 4G speeds with a fair-use allowance above 5 GB, the correct purchase is nothing, and no eSIM article will ever tell you that because there is no commission in it.

You are on a cruise that stops in Ushuaia for eight hours. Eight hours is a port day, the ship has Wi-Fi, and the town has cafés. Buy nothing.

You are in Argentina for a conference that provides Wi-Fi and you never leave the venue. Buy nothing.

You are transiting. A two-hour connection at Ezeiza does not need a data plan, and a plan bought for a connection will activate against the Argentine network the moment your phone attaches, which means you burn a day of a seven-day plan sitting in a terminal.

The inverse is worth stating too: the profile of a traveller who definitely needs a plan is anyone whose first act after landing is a rideshare, a bus ticket or a hotel check-in that requires a phone number. That is most people, and it is why the category exists.

How do you avoid buying the wrong tier twice?

Two rules, both learned from the arithmetic above rather than from any provider’s advice.

Rule one: buy the tier one size above your estimate, once. Every provider’s ladder is priced so that the step up is cheaper than a second purchase. Nomad’s 10 GB is $28 and its 20 GB is $47 — the step costs $19 for ten more gigabytes, or $1.90 each, against a top-up rate that is always worse. Buying twice never wins.

Rule two: buy a duration that outlasts the trip, not one that matches it. A seven-day plan for a seven-day trip expires on the morning of day seven if it activates at 09:00 on day one, which is the day you fly home and want a boarding pass. Buy ten days for a seven-day trip. The extra three cost $4 at Airalo and $7.10 at Roamless, and they remove the only failure mode that is guaranteed to happen rather than merely possible.

Between those two rules, the decision collapses to a single question: which provider has the cheapest tier above your estimate at the longest duration you can afford. For most Argentina trips that is a metered plan near 10 GB from Ubigi or Nomad, or Airalo’s ten-day unlimited if you would rather not count gigabytes at all.

Which questions come up before an Argentina eSIM checkout?

Is an Argentina eSIM cheaper than a local SIM card? Almost never on data alone, because Argentine mobile data is among the cheapest in the world at about $1.11 a gigabyte on average. It is cheaper once you count the detour: a $6 round trip to a carrier store, an hour of registration, and a decent chance that a foreign card is declined at the counter. Under about 5 GB of use the travel plan wins on total cost, not just on convenience.

Do I need to show a passport for an eSIM in Argentina? No. Registration under ENACOM’s nominatividad rules applies to lines sold in Argentina; a profile bought abroad from a reseller is activated against a foreign-issued identity and never enters that process. This is the single largest practical difference between the two routes.

Will an Argentine eSIM work in Uruguay or Chile? Not on a single-country plan. The profile stops registering at the border, which for Uruguay means mid-river on the ferry. The two-country options are priced there in full, and the Chilean side of the Andes has its own catalogue.

How much data does a two-week trip actually use? Between 8 and 15 GB for normal tourist behaviour with hotel Wi-Fi in the evenings. The single biggest determinant is not your itinerary but whether your camera roll backs up over mobile data.

Which network will I be on? Movistar, for five of the six — Holafly names Telefónica, which owns the Movistar brand, so that is the same network under its corporate name. Ubigi adds Personal as a second network, and Saily declines to say. Whether Movistar is the right network for your route is a different question and lives in the carrier guide.

Is 5G available? In Buenos Aires and a handful of other cities, yes — Personal measured a 518.8 Mbps median on 5G. Outside them you will spend the trip on 4G, which is why the national all-technology figure of 67.79 Mbps is the number to plan with.

Can I use my plan in Argentina and then in Brazil on the same trip? Only with a regional plan. A single-country Argentine profile will not attach in Brazil, and the Iguazú crossing puts you in Brazil for a day trip without warning.

What if the plan does not connect when I land? Nine times in ten the travel line is not selected for mobile data, or data roaming is off on that line. Check both before anything else; the rest of the sequence is in the activation troubleshooting guide.

So which Argentina eSIM should you actually buy?

If you are in Argentina for less than two weeks, buy a metered plan one tier above your estimate from the provider with the cheapest per-gigabyte rate at that tier — Ubigi at 10 GB, Nomad at 20 GB — and install it before you fly. If you want no counting, Airalo’s ten-day unlimited at $38.50 is the best large-data product in the country at $1.28 per usable gigabyte, provided your trip fits inside ten days. If your trip does not fit inside ten days, that constraint is worth more of your attention than the price difference.

If you are staying longer than a fortnight, the local chip wins and the detour is worth it: bring cash, find a carrier store rather than a kiosk, and expect to show a passport.

And if a plan you are looking at says unlimited with no daily figure on the page, assume 3 GB a day until the provider says otherwise. In Argentina, that assumption has been right every time it has been tested.

Before you pay, run the handset against the compatibility list — a carrier-locked phone will refuse every one of these profiles — and if you are still choosing between countries rather than plans, the South America regional pricing is where the multi-country arithmetic lives.