Argentina

Basics
Argentina has three (soon 4) national operators: They three all have about the same market share. Plans are pretty much alike for the three of them and the coverages are similar. 2G and 3G is on 850 and 1900 MHz, so users from Europe and Asia need a "US-band" device. 4G/LTE is on AWS (1700/2100) MHz and B28 (700 APT - being currently only used by Personal).
 * Claro (by América Móvil)
 * Movistar (by Telefónica Spain)
 * Personal (by Telecom Argentina)
 * [Nextel - 4G/LTE only, to be deployed]

A fourth provider called Nextel was aquired by media conglomerate Grupo Clarin in 2017 and will provide a 4G/LTE network soon based on 900 and 2500 MHz frequencies.

Generally data is pretty slow and 3G coverage variable, although they have greatly improved in areas with 4G availability. In Argentina WiFi is available almost everywhere. According to OpenSignal's country report, Personal has the best overall perfomance in the country, while Movistar has the best 4G coverage at somewhat lower speeds in 2016.

The first MVNOs started with Nuestro and Quam, now renamed in Tuenti móvil, but don't offer good data choices for visitors so far.

Regulations
Prepaid SIM cards are not registered until now. This may change soon as operators will need to verify and identify all mobile phone users via a central register with a view to reducing the trafficking of stolen handsets. The new rules require that the operators themselves must pay to 'develop, operate and manage' the register, which is being set after regulator Enacom ordered all mobile service providers to block equipment reported as lost or stolen.

In 2014 the government of the former president Cristina Kirchner set up a national prepaid plan called Plan prepago nacional to mitigate the effects of surging inflation. This programme establishes set prices that are up to 67% lower than average prepaid plans for voice calls, mobile data and SMS and around 718,000 users have signed up. It has been extened until April 2017, but is often not offered to tourists. That's why you see two tariffs mentioned under each provider.

Dialing rules
For calls and SMS Argentina has somewhat unusual dialing rules: Mobile phone numbers in Argentina are always preceded by a two digit number, usually '15' or '11.' If you’re calling a mobile number from a landline, you’ll have to dial the two digit number (e.g. '15') first (add the area code before the '15' as necessary). However, if you’re calling a cell phone from another cell phone, you don’t need to dial '15' and you also don't need to dial '15' to send SMS. When dialing an Argentine cell phone from another country, dial your international exit code, then 54, then 9, then the area code without the 0, then the number – leaving out the 15. It's confusing.

Claro
Claro (formerly called CTI Movil) owned by Mexican América Móvil is still market leader by a small margin amd has a good coverage: 2G 3G and 4G coverage maps

Availability
You can buy prepaid SIMs (called chips) at Claro Customer Care Centers (shop locator), kiosks, pharmacies, service stations, supermarkets, any outlets or shops where you can see the logo of Claro. For 4G/LTE you'll need an USIM card.

They sell different chips for smartphones, tablets and computers (modems). Start-up price for the SIM card is around $20-50.

Top-up with vouchers calles Tarjetas Prepagas sold everywhere by texting the voucher code to 444. Or do a virtual recharge available in many kiosks and supermarkets starting at $5. Check balance by *611#.

Data rates
Default data is according to these rates: Once the quota is reached, speed will be reduced to 128 kbps. You can restart high speed volume up to 3 times a day by texting 'TURBO' to 252. For this, the same amount will be deducted.
 * daily (0-24h per calendar day) flat of 50 MB for $ 8 in Plan prepago tripilica
 * daily (0-24h per calendar day) flat of 50 MB for $ 4.59 in Plan prepago nacional

Data feature packs
The following data packages are offered by texting the activation code to 454 or making a selection in *989# or in the Mi Claro App:

More info

 * APN: igprs.claro.com.ar
 * Username: clarogprs
 * Password: clarogprs999
 * Website in Spanish: http://www.claro.com.ar/

Movistar
Movistar is owned by Spanish Telefónica and still the No.2 in the country what customers are concerned. It has the widest 4G/LTE coverage in the country covering 68% of population in 2016. 4G service is available in more than 380 locations, including all 23 provincial capitals and the national capital.

Availability
Chips and recharges are sold in their shops and outlets. They are also often available from kiosks for around $20-50 (though these are often re-used old numbers, which may include previous premium SMS subscriptions. Register on the Movistar site, so you can check that you are not losing credit).

For recharges you will be awarded bonuses: For a $50-80 reload you get $30 bonus and $100-180 gives you $80 bonus for the Multiplicate plan (see below). To check balance, send any SMS to 444.

Default data rates
They offer two prepaid plans: Like Claro, Movistar has daily (0-24h per calendar day) 'flat' rates for prepaid called Internet Día including a 50 MB block that lasts until midnight. When you start using internet, you will be billed automatically once per day for the first block and you will receive a SMS saying “Y''a estas navegando con INTERNET x DÍA PLUS! Tenes 50MB para navegar hasta las 0 hs por $6,50 (o $3,81).''
 * Plan Prepago Multiplicate: daily data pack at $ 7.50
 * Plan Prepago Nacional: daily data pack at $ 3.81

When 50 MB is used up, you will get another SMS from 772 ''Alcanzaste los MB disponibles y se reducira la velocidad. Responde SI y recuperala x $6,50 (o $3,80) cada 50 MB con Internet por dia Plus y segui navegando hasta las 0hs''. Just reply SI to 772 to buy a new block of 50 MB.

If you don't add further blocks then you still have internet access for the remainder of the day, but at a reduced speed of 32 kbps only. Detailed info about blocks can be found (in Spanish only) here.

Data feature packs
Following Data-only packages are offered:
 * $ 35 per week you get 50 MB per day valid for 7 days. Activation by texting 'Internet' to 2345.
 * $ 30 for 3 days you get 300 MB of data. Activation by texting 'D3' to 2345
 * $ 60 for 7 days you get 700 MB of data. Activation by texting 'D7' to 2345

Roaming
On the their new promotion 'Roaming all inclusive' you can roam for US$ 7 per 24 hours in the Telefónica networks in Germany, the UK (both on O2), Brazil (on Vivo), Bolivia, Chile, Colombia, Costa Rica, Ecuador, El Salvador, Spain, Guatemala, Mexico, Nicaragua, Panama, Paraguay, Peru, Uruguay, Venezuela (all on Movistar) and in the United States with up to 200 MB and in most countries up to 4G speeds, before you will be throttled to 256 kbps. This option is automatically enabled when entering one of these countries and having a balance above US$ 7 in Peso.

Data-only SIM
For tablets and modems they sell their data-only plan Internet Prepago with one option only: 200 MB data in up to 4G speed for the rest of the day until midnight at $ 18. This is automatically enabled as soon as you connect to the net. After having used 200 MB you will receive a SMS. This is auto-renewed unless you text 'NO' or 'OPTION' to 772. Then you can release another 200 MB only by confirming 'SI' to 772.

More info

 * APN: wap.gprs.unifon.com.ar
 * Password and Username: wap
 * Website in Spanish: http://www.movistar.com.ar/

Personal
Personal has 4G/LTE in 22 cities across 16 provinces, and is available for all plans (including prepaid) in 2016. It's the only Argentinian carrier so far that's using band 28 on 700 MHz (not compatible to 700 MHz on US bands) and 1700/2100 MHz (compatible to US bands) for 4G/LTE.

Although being only no.3 in the country OpenSignal gives it the best nationwide performance. Note that their customer service is not available in English. About 90% of the Buenos Aires metro system (called Subte) is covered by Personal's 4G/LTE. At the end of 2017 it has 71% coverage of population in over 1000 towns and cities.

Availablility
Chips and recharges are sold in their shops and outlets (shop locator) at $ 20-40, and the same shops around the city that all other companies and come with $10 credit after activation.

Vouchers for top-ups calles Recargas Prepagas of $ 30, 40 or 50 or electronic top-ups in many kiosks and supermarkets. Check balance by *150#.

Default data rates
They have different prepaid plans on offer: Add 1% tax to all rates. On all three plans they sell you packs for a calendar day until midnight. When used up, you can buy another pack or will be throttled to 32 kbps.
 * Prepago Nacional: data $ 7.99 per day for 50 MB
 * Personal con Tarjeta: data $ 4.37 per day for 50 MB
 * Plan Digital Tarjeta: data $ 12 per day for 100 MB

At midnight, you get a text message like this, saying your 50 MB data plan has been renewed: ''Comenzaste a navegar, ya contas con 50MB hasta las 23:59hs. Se descontó 7,99 pesos final de tu crédito''.

When your data runs out you get another message to extend the plan and get another 50 MB: ''Alcanzaste tu cuota de datos. Enviá SI al 152 para mantener tu velocidad de navegación por otros 50MB hasta las 23.59hs. Precio 7,99 final.'' You need to text 'SI' to 152 to purchase another 50 MB of data for $ 7.99.

Personal has now unlimited data for WhatsApp (messages, voice messages, photos and videos included) according to how much money you top-up ($30-49 will give you 1 day, $50-99 will give you 5 days and >$100 will give you 15 days)

Data feature packs
You can add weekly or monthly data packages called Pack Simple: Speed will be reduced in both packs to 32 kbps when using more than 50 MB per day, but you can extend them like the default rate.
 * 'unlimited' internet for 7 days at $ 34.90 by texting 'ACT SIMPLE' to 152
 * 'unlimited' internet for 30 days at $ 109.90 by texting 'ACT INTERNET30' to 152.

More info

 * APN: datos.personal.com
 * Username and Password: datos
 * MCC: 722
 * MNC: 34
 * Website in Spanish: http://www.personal.com.ar/

Nuestro
Nuestro was the first MVNO in the country at all. It uses the network of Personal (see above). SIM cards can be obtained in their shops (list). That's where you find their recharge vouchers of $20 or $30 too.

They have different plans called Hablemos Más or Tuyo. But they don't include data. In fact, they don't even sell data packages and data stays on all plans at a default rate of $0.005 per 5 KB.
 * APN: gprs.nuestro.com
 * Username: gprs
 * Password: adgj
 * Website in Spanish: http://www.nuestro.com.ar/

Tuenti móvil(formerly Quam)
Tuenti móvil (formerly called Quam) is the biggest MVNO in Argentina, started at the end of 2013 as a subsidiary by Telefónica. It targets primarily young people and uses the network of Movistar. But they are not recommended for foreigner. While you can buy the SIM at many newspaper kiosks only to find out that you can't register it.

'''As a foreigner without a valid Argentinian ID (= DNI), you won't be able to activate your SIM card. For registration an Argentinian DNI number is essential. That's why Tuenti Móvil is taken off the list at this time.''' Please report, if you have been able to register a SIM card as a foreigner and how you did it.