Mobile phones - Mobile phones

Mobile phones can be an excellent tool for keeping in touch while travelling. Given advancements in technology, in addition to providing phone service they also act as tools to capture and share moments from your trips as well as help you find information about places whilst on the move and book a variety of travel services.

Mobile phone basics

The main ways you can use a cell phone while travelling overseas include:

1. Taking your phone and SIM card, and use the foreign network (roaming)
2. Purchasing a SIM card at your destination, and put it in your own phone
3. Renting or purchasing a phone and SIM card at your destination
4. Renting or purchasing an international cell phone and SIM card prior to departure

Depending on the length of your trip, it may make sense to buy a local pre-paid mobile telephone at destination or a local SIM card for use in your existing mobile device.

Roaming with your existing phone and SIM card may be manageable when visiting one European Union country from another, but further abroad (even in countries that neighbour the EU) the cost may be prohibitive or the service not available. Pre-paid SIM cards used to be cheap (€10 or less with credit included) and widely available in the EU until 2016, when legislation banned anonymous pre-paid SIM cards. Buying a pre-paid SIM now requires identification of the buyer (name and address verification through bank card, Paypal etc.), making it practically difficult or impossible to acquire or use anonymous SIMs in the EU. In some countries (e.g. Italy) a local tax code may be necessary as well.

In some countries, such as Mexico, there are roaming charges even within the same country. If you buy a local SIM-card, make sure it is possible to use it without roaming in all places you want to visit.

Bring your phone

Handset with slots for dual-standby SIM and microSD, allowing using both a domestic and a local number without swapping SIMs

The beautiful thing about standards is that there are so many to choose from. There is a vast selection of mobile networks and handsets that not only aren't on the same wavelength, but aren't even speaking the same digital language. Fortunately, if you have a smartphone purchased in the last couple of years, the chances that it will work internationally have improved slightly. Nonetheless, it's worth checking the compatibility before you leave.

There are various "generations" of mobile telephone which contain multiple, sometimes-incompatible standards. Each generation represents around 10 years in mobile phone technology:

• 1G was analogue mobile phone services, such as NMT and AMPS. Shut off circa 2008; now dead.
• 2G is the first batch of digital mobile phones. There are at least two standards which do not interoperate at all:
  • GSM was the most widely used mobile phone standard in the world, originating in Europe in 1991. GSM has been made largely obsolete by 3G and 4G; many telcos have shut down their GSM networks, and more will do so through 2024.
  • CDMA (more specifically cdmaOne) is a standard still used foremost by a few incumbent US telephone companies, including Verizon and Sprint, and the only 2G mobile phone standard used in South Korea. However, it is being decommissioned over the next couple of years. The main Canadian telcos have shut their CDMA networks down, and the U.S. and South Korea are following suit by 2020-2021.
  • PDC was a standard that was exclusive to Japan, and also the most widely-used 2G standard used in the country. This unique standard meant that foreign mobile phones could not be used in Japan and vice versa. The last network was shut down in 2012.
• 3G was an advancement that was similarly split into two formats.
  • Most networks used UMTS or its variants, an evolution of GSM. W-CDMA is the original version of UMTS; HSPA/HSPDA and HSPA are UMTS upgraded for faster Internet data downloads. As many carriers gradually replace GSM, a handset with 3G is likely to work abroad in places where GSM-only handsets do not.
  • Just like 2G, a minority of networks used CDMA2000 (specifically EV-DO), an evolution of CDMA. Many of these have already shut down, and of the remaining few, around half will be decommissioned in 2020-2024.
  • As the concept of a "generation" of mobile handsets is largely defined by marketers, some advertised CDMA2000 1X (a faster CDMA) or EDGE (a faster GSM) as "third generation", "3G" or "3x". These standards are not UMTS or EV-DO; the respective incompatibility issues of GSM vs. CDMA all remain in EDGE and EV-DO.
  • The same blurred boundaries between "generations" exist with HSPA (a faster 3G UMTS branded occasionally as 3.5G or 4G).
  • Modern smartphones entered the market in the latter half of the 3G era. Unless you have a very early-model smartphone (e.g. the first-generation iPhone), there is a very good chance your smartphone is at least 3G-capable.
• 4G is a faster data connection (usually LTE) available in major cities and supported by most modern smartphones. Frequency bands vary by region; some handsets support half a dozen options. As of 2017, all 4G providers or handsets also support 3G standards; most handsets can also fall back to GSM if the network supports it.
  • WiMax was a standard used by Sprint, and now fully decommissioned.
  • TD-LTE (in some parts of China) are 4G but not compatible with standard LTE.
• 5G networks have rolling out to certain locations since 2019. As of 2020, China leads the world in 5G mobile phone technology.

There are also multiple frequencies. A handset which lacks the local frequencies or does not use a compatible standard will not connect to the network. Again, the more modern your phone the more likely it is to work across frequencies.

Outside the Americas:

• 900 MHz and 1800 MHz are the most common GSM frequencies
• 900 MHz and 2100 MHz are the most common 3G (UMTS) frequencies
• In Australia, 1800 MHz used for 4G. 850 MHz provides good 3G UMTS (Telstra) coverage.

In the Americas (ITU zone 2):

• 850 MHz and 1900 MHz, the most common GSM or CDMA frequencies, are used for 3G (UMTS) on AT&T and all Canadian major carriers (Bell, Rogers, Telus)
• 1700 MHz and 2100 MHz are used for 3G (UMTS) on the US T-Mobile network
• 1700 MHz was used for Canadian new entrants, regional carriers (Eastlink, Vidéotron) and 4G (LTE) services.
• Additional bands (such as 2600 MHz) may be used for 4G LTE to carry high-speed data

If your phone matches all frequencies of the telco network in the country you are travelling to, it should receive a good signal when roaming or with a local SIM card. If your phone only matches one of the frequencies, it may only work in some locations.

The last thing to check is the SIM (subscriber identity module), a small card which assigns a carrier and telephone number to a handset. There are two options for using your existing handset abroad:

• Roaming leaves your existing SIM and carrier in place, relying on agreements between your home carrier and a carrier at your destination to route calls using your existing mobile telephone number. This gets expensive, as billing goes through two telephone companies; any calls to you have to go to your home country first, then back out internationally, further inflating cost. This may be a viable option if visiting one European Union country from elsewhere within the EU, as regulators have cracked down on the worst of the billing abuses. Elsewhere, it can be costly and normally will not be permitted at all on prepaid cash mobile plans. In some cases there may even be roaming surcharges without crossing national boundaries. This is especially true in countries with weak regulations or where one or a handful of companies have "cornered" the market; regional carrier handsets may "roam" when taken to domestic locations outside a limited home region.
• Obtaining a local SIM allows the traveller to obtain a local prepaid plan with a local mobile telephone number at local prices. This won't work if a handset has been locked to only accept one provider, although codes to unlock many common handsets may be purchased from third-party sites online.

Some handsets are made specifically for use with multiple providers. These are known as "dual SIM" as they have two card slots; some are effectively two-line phones on which each virtual line can be subscribed to a different number, different provider or different country. The capabilities of these devices vary. A modern dual-SIM phone will allow you have your domestic SIM roaming to receive texts, etc on your home number, and have a local SIM to access calls and data more cheaply.

Due to upgrades, many travellers have old handsets which are still functional. If this has the local frequencies, bring it; one handset keeps your existing home number active while the other takes advantage of reduced costs with a local SIM card. If a call arrives for your main number, call back from the local SIM at local prices instead of paying the higher fee for roaming. In areas with thieves, you may also want to avoid flashing your latest model phone.

If you are travelling with an older phone, you may have more issues with compatibility than with modern ones.

Roaming

Using your phone in places other than its home area is called roaming. if you intend roaming, you should do your homework before you travel. You need to understand the price and what is included. If you're roaming the cost may be no different to home (e.g. most EU-based subscriber roaming within the EU), you may be able to pay a fixed fee per day, or the cost can be thousands of dollars for only moderate usage – depending on your carrier, contract and destination. You can pay to make calls, to collect voicemail, and even if someone calls you and is diverted to voicemail. Background data can accrue costs from the second you turn your phone on.

Consider using text messaging (SMS) as a cheaper alternative to making per-minute phone calls. These text messages can be sent between phones, with up to 160 bytes per message (messages can nowadays be longer, but are still delivered and paid for in such chunks). While SMS messages can be more expensive when overseas (from USD 0.30 to 1.00 each), they are cheaper than international calls and can be very useful for keeping costs down. Sometimes receiving them can be free. Moreover, those who send you an SMS using a carrier back home will be charged at local rates.

There are two things you have to check to ensure that roaming will work when you arrive:

1. Is your phone the correct type and can it communicate on the frequencies required by the foreign network?
2. Does your home carrier have roaming agreements with at least one carrier in the country you are visiting, and are you on a plan permitted to roam to another country?

Your phone

While roaming on your existing carrier lets you bring your home number with you, your phone must support the standards and frequencies of a network at your destination with which your carrier has a roaming agreement.

There is no need to unlock the handset or replace the SIM card, but if you're on the wrong frequencies or carry a CDMA-only handset into a country whose providers only support GSM, you will have no signal. Your home carrier should be able to tell you what networks are supported on your handset and plan.

Your carrier

Your carrier must have an agreement with a carrier at your destination to allow you to roam. Check that an agreement is in place and what frequencies the roaming carrier uses against the capabilities of your phone.

• Official EU roaming information page – for EU related information (tariffs, hints). Although in most cases EU usage supposed is billed against a subscriber's allowance, some exceptions apply, especially for providers that offer mobile data for bargain basement rates.

Check that your plan allows international roaming. It may need to be enabled, which is much easier to accomplish before you leave home. Many pre-paid plans do not permit any form of international roaming, limit the networks that you can roam to or limit enabled services (such as SMS only).

Most phones default to a setting which automatically chooses a network for roaming. When in areas near the border of your home country or intended destination, it may be worthwhile to change the setting to manual, and to keep to your home network until you lose the signal. The farther away from the border, the weaker your home carrier's signal; depending on terrain you might loose the signal already before the border, and likely at latest 5 mi (8 km) beyond it – but you avoid your phone picking up an expensive network across the border when your domestic one still works or when you don't need to be connected.

The foreign signal may actually be stronger also without crossing the border, especially in mountainous terrain, where the domestic signal is unreliable, where the signal path to the foreign tower is directly across water, and in backcountry, where no domestic towers are near. Mobile users in border regions like Niagara Falls, Windsor–Detroit or the Thousand Islands often disable roaming from the phone's menus to avoid being randomly hit with roaming charges on mobile telephones which never left their home country.

Rip-off networks

There are an increasing number of localized nano networks (especially in Europe) that may, unbeknownst to you, "capture" your mobile if you have set it to "automatic" network selection. For example, if you are travelling on a Stena line ferry the few miles between Scotland and Northern Ireland, the strongest signal is likely to be their own network with roaming charges of more than €1.50/min for incoming calls rather than the €0.05/min that the call would be capped at if you were still using an EU network. Cinemas have now got in on the act and are abusing what was once a socially useful technical advancement to stop phones ringing during performances.

At sea, out of contact with normal carriers, a ship-local network connected by satellite may truly be a service for those needing it, but the prices may be outrageous for those who could get by without – or when automatically switched to when land based networks are still in reach (even in the harbour).

Local and international SIM Cards

Mobile phone with battery removed, mini-SIM at the location where it is to be inserted.

Local pre-paid (sometimes known as "pay as you go") SIM cards are often a much cheaper alternative to roaming. If staying a longer time, a normal local subscription may also be an option.

While a local SIM is usually much cheaper for local calls than roaming, other considerations may apply for calls from or to abroad, such as to friends at home. You have the options of having them call your normal number (and your paying a surcharge for the international call), them calling your local number (paying for an international call), your calling them with your normal number (an international call while roaming, possibly treated as a special case), or your calling them with your local number (what are the fees for international calls on your prepaid plan?). The fees for the four options may differ significantly.

A SIM is a card which is inserted into an UMTS or GSM handset (often under the battery). It is necessary on GSM phones, where it provides the handset's identity as seen by the network. In CDMA handsets the functionality was integrated, but most now accept SIMs (or the R-UIM or CSIM variety).

The cards offer some memory for the phone's applications. For example, your contacts may be either in the memory of the phone itself or on your SIM, unavailable if you change SIMs. Copy relevant info to the phone if possible, and to paper (interpreting the info may depend on features not available on the local SIM).

With a local SIM, the phone – unless locked to the original carrier – is treated like a domestic one, with a local telephone number. Some prepaid cards include a small amount of prepaid airtime (typically no more than half the face value of the card, sometimes even more). The value of the airtime of course depends on call and data fees, which may differ from those typical on non-prepaid subscriptions.

Prepaid SIM cards usually require no account setup, credit card numbers or bank accounts. In some countries, passports or IDs are necessary (to reduce use of phones by criminals); a handful restrict purchase of mobile numbers by non-residents.

To add credit to these SIM cards, buy "refill" (the common term in the US), "top up" (Singapore, the UK, Canada and New Zealand), "recharge" (Hong Kong and Australia), "reload" (Philippines) or "add value" cards or vouchers from news stands, telephone stores or convenience stores. ATM or online credit card top-ups may be possible with some providers; however doing so through their websites may require the user to have a domestic debit/credit card or bank account. In some countries, credit (prepaid or plan) may be transferred between users of the same network by sending an SMS to the provider.

In some large international airports, outside security, mobile phone shops will offer a prepaid SIM without leaving the airport. A few vendors offer SIM cards intended specifically for visitors.

As a prepaid product, the SIM card and the credits have limited lifespans. Unless periodically reloaded (usually with a code purchased from a local store or on a website with a local credit card) the SIM and the local telephone number will expire. As a general rule, lower top-up denominations tend to expire more quickly.

The card is packaged as a debit card-sized piece of plastic from which you can break out a smaller chip card in one of three sizes (mini SIM, micro SIM, nano SIM). The chip is the same, there's just less plastic frame around a SIM in the micro or nano size versions used by some phone models. Some very old phones may require a mini SIM a little thicker than those including nano versions, check if relevant for you.

A local SIM means one more number that you need to inform important contacts about; if you intend to visit many countries it may be easier to obtain a service which can be call-forwarded cheaply (such as a Voice over IP provider), distribute that number to your contacts and forward its calls to your local mobile phone/SIM when you enter a new country.

Some phones can accommodate two SIM cards, which can either be used simultaneously, by choosing on the go, or by choosing on startup, depending on phone model. With such a setup you can get messages sent to your domestic number, in some setups also see missed calls, and call back using your local SIM, without having to swap SIMs physically. You could also use a second phone with the local SIM.

US-network SIM cards are sold by several vendors in Canada; Roam Mobility issues a T-Mobile prepaid SIM which can be activated for as little as one day every six months, while Telgo.ca issues a similar AT&T prepaid SIM. These cost C$3–5/day, depending on whether you want mobile data or just voice.

While voice calls should work as soon as you install a subscribed SIM card and re-apply power to the handset, data may require various settings to be configured so that the handset can find the Internet gateway. Usually the set-up is automatic, using data on the SIM card, but sometimes it has to be done manually. For example, Rogers (Canada) provides this list of provider-specific settings:

APN: rogers-core-appl1.apn

MMSC: http://mms.gprs.rogers.com

MMS Proxy: mmsproxy.rogers.com

MMS Port: 80

APN Type: Default

APN Protocol: IPv4/IPv6

APN Roaming Protocol: IPv4/IPv6

If you are buying a SIM card, it may be worthwhile purchasing from a telco outlet so your phone can be working before you leave. This will save any confusion with having to apply settings yourself. Otherwise you may have to check the providers website, which can be difficult if you don't have mobile data configured. A few providers may also supply a username and password for mobile data. Carrier technical support is usually limited to providing a list of settings and advising you to ask your handset manufacturer. While MMS might only be needed for a specific few applications (usually, sending photos by text message), if you leave out the access point name (APN) you have no mobile data. Handsets purchased from individual providers usually preload the settings for that provider, but if you bring your own unlocked handset, you need to add your local SIM provider to the connection list for data. There may also be a setting to point the mobile browser to the new connection on the list, instead of your home carrier's gateway.

If your handset gives one-button access to voicemail, there is a number (listed in the configuration menu) which is auto-dialled by that feature. This number usually is read from the local SIM, but it's best to verify. Any on-screen "message waiting" indicators will only work for the currently-installed SIM, even if messages are waiting on your home provider (original SIM) and local provider (local SIM). Some handsets also use memory space on the SIM to store phonebook entries or Wi-Fi passwords; swap SIM cards and you may need to copy or re-enter this data.

Another alternative is an "international card"; these usually allow free or cheap incoming calls in a significant number of countries and offer relatively cheap outgoing calls via an automatic callback service. Their phone numbers are usually based in the British Isles or Estonia. There are many different ones available, so shop around; the cards sold at airports may not be the cheapest. This avoids multiple changes of numbers.

Locked and unlocked phones

If you want to use your own phone, you have to check (see above) that the phone can be used at your destination, type and communication frequencies and that it is unlocked (or "carrier SIM-locked".)

In some countries, providers may be required to provide subscribers with the unlock code for devices they own after a certain time period, usually for a fee. For many (but not all) common handsets, an "unlock" code may be purchased more cheaply from a wide selection of Internet vendors (typically US$10–20); more rarely a handset must be taken to a specialized vendor to be unlocked.

In Canada, beginning Dec 2017, cellphone customers can ask their provider to unlock their phones free of charge, and all newly purchased mobile devices must be provided to customers unlocked.

Unlocking a phone (to allow access to competing mobile carriers) is not the same as "jailbreaking" (which allow access to non-Apple software downloads on Apple devices) or "rooting" (which provides a "run as administrator" option for Android programs). Some phones are easier to unlock than others. Older Nokia phones can be unlocked at home with a simple code, while Motorola or Sony phones require additional equipment and may require you to bring your phone to someone. Some (Japanese domestic market phones) may use a different SIM-based method that attaches to your SIM, allowing you to take it from phone to phone. Shop around: unlocking services are generally cheaper and more easily available in Europe and Asia than in North America.

An alternative is to buy an unlocked phone. In some countries — for example China — phones are never locked. Various web sites and some shops in Western countries sell unlocked phones, usually at somewhat higher prices than the "deals" you can get by signing a contract for a service and taking a locked phone. Travel-specific capabilities like "quad-band", "dual SIM" or travel chargers, intended to keep handsets working on multiple carriers in multiple countries, are more likely to be available on factory-unlocked handsets from third-party electronics vendors. An unlocked 3G (UMTS/WCDMA) dual-SIM quad-band Android handset with no carrier-specific branding may cost anywhere from US$150 to 500 from an online mail-order house, depending on brand name and capabilities.

Calls over Internet

Smartphones may be able to place voice-over-IP calls using a wireless Internet hotspot (or, with the right software, any decent Internet connection) by installing a softphone application and signing up to a VoIP provider. This is an inexpensive way to talk unless your Internet connection is expensive; when calling someone who's also using an Internet phone or app connected to the same servers, it may even be free.

VoIP calls are independent of the local cellular telephone networks, but are limited by the availability of Internet connectivity, and sometimes blocked at the Internet firewall. If your Internet connection is by mobile data, these VoIP calls can be anything from free to expensive, depending on your mobile phone provider. In addition to voice they may offer video, text chat and file transfer connections to compatible applications.

Internet voice providers tend to fall into two categories: Some are generic Voice-over-IP gateways which follow an Internet standard (SIP) and allow calls to regular phone lines from users of any application which follows the standard – often for as little as a penny or two per minute, with no minimums (many small independents fall into this category; in the US, Google Voice may be another option). Others are proprietary apps (such as WhatsApp, Viber, Skype, or Facebook Messenger), foremost connecting users of the same service, with calls to other systems usually treated as calls to the switched telephone network. The apps are downloadable from the app store for your phone operating system, most often for free.

Renting or purchasing a phone abroad

You might want to use a separate phone to use with a local SIM, because your phone does not support the local network, because you want to continue to use your domestic number, or because you want to use a cheaper phone on the road. If you buy that phone before departure, you should check its compatibility, if you plan to buy it after arrival, check where they can be bought and plan for getting along until you have it.

You can often rent a local mobile phone, often even at the airport on arrival. However, in many countries purchasing a cheap phone and a pre-paid SIM will be more economical (even if used for just a week) as airport rental companies often charge much more per-minute than the local prepaid rates. Airport rental kiosks might be closed to travellers arriving on late night flights and may run out of phones during popular events in high travel season.

In some destinations, providers market artificially-cheap prepaid handsets (in the US, "AT&T GoPhone" handsets start at $20 when the SIM alone is $10) but SIM-lock the handset to one provider which charges full price for the prepaid minutes. Unless the phone can be unlocked, it will not be usable with another carrier’s SIM card on your return and should be treated as disposable. If you are going to other countries, you might want to buy an unlocked phone separately.

Especially in low-income countries or areas were theft and other types of crime are common, a major advantage of getting a cheap "disposable" pre-paid phone is that even if your phone is stolen you lose only the (relatively low) value of your phone and the remaining balance on the chip – and messages, call history and whatever else you stored on it – not the several hundred euro a new model smart phone might have cost you.

But if you intend to use a local phone and call local numbers, you might want to familiarize yourself with the local system and rates. In some countries those are not self-explanatory and you may find your balance "disappearing" after just a few days of not calling anybody or other shenanigans played on you by a dominant company, especially in countries with weak or no government regulations to prohibit such business practices.

You might also check the procedure to activate your newly purchased phone: some models require you to register, accept terms and download updates, for which you may need or want working Wi-Fi, which may not be available where you buy the phone, or even at your lodging. If the phone is set to use a local language by default, you might need help to change language settings.

Renting or purchasing a phone before departure

By having your phone and SIM before you go, you will have your phone number to give out to family, friends and co-workers. You will have a phone that is ready to use as soon as you land. Your handset will come with complete operating instructions in your language, with information on how to check the remaining prepaid credit balance, how to add additional credit, how to contact customer service, and how to make and receive international calls.

This of course requires that you can get a compatible phone and SIM at home. These are not necessarily sold in the local shops, and may in any case be more expensive than they would be at the destination.

Purchasing a USB charger

A typical USB-C charger. Note that not all chargers provide the same support for features such as fast charging, which could affect some devices with high power consumption. Although sold as a package, the cable and charger can be swapped independently if physically separate like here.

Mobile device makers, in response to EU pressure, have been migrating to 5V USB as a standard connection for recharging handsets. It should be relatively easy to find a USB charger compatible with local electrical systems at your destination, or recharge from your laptop or any local computer. You will still need the cable connecting your phone to the USB contact on the charger. These are not fully standardized:

• The former de facto Android standard of microUSB is now found only in older phones and a few low-priced models.
• Most Apple devices use a proprietary connector, with recent phones and most iPads using the Lightning connector.
• Most non-Apple phones, as well as newer Apple tablets (specifically post-2018 iPad Pros and the 2020 iPad Air), have migrated to USB-C, whose connectors are not compatible with earlier USB iterations.

Some chargers have the cable inseparable from the charger. This offers less flexibility. If there is a standard USB outlet on the charger, and the corresponding standard connector on that end of your independent cable, you can continue using your cable with the new charger you buy across the border – and so can your friend, with their own cable. When you buy the new charger, you just have to check it has the USB outlet, you don't have to buy one that has the right cable. If it has, all the better, now you have a spare.

Information by region

Please see the Contact section of the destination country article for information on communications specific to one country.

North America

Frequencies in the Americas (ITU region 2, in blue) differ from the other continents

GSM (from the handful of major North American carriers that offer it) operates most often on 850 MHz/1900 MHz. AT&T and all three Canadian majors (Bell/Telus, Rogers) use 850 MHz/1900 MHz for their 3G (UMTS/WCDMA) networks. These are not the standard frequencies on other continents. Additional frequencies are used by new entrants, regional carriers or high-speed mobile data services.

AT&T and T-Mobile (USA) are GSM, as is Rogers (Canada). European handsets might roam onto these carriers (for a price, usually fairly steep) if they support local frequencies and the home carrier permits it. 3G (UMTS/WCDMA) is supported by more carriers than GSM, but frequency assignments vary widely. An unlocked quad-band GSM or UMTS handset should be able to take a local SIM at destination. AT&T shut down its 2G network in 2017 and will shut down 3G no later than the end of 2022. T-Mobile, which purchased Sprint in 2020 and has now folded the Sprint brand into its own (though the two networks will not be fully integrated until about 2023), plans to shut down its 2G network by the end of 2020.

Many American carriers and resellers (Verizon, Alltel, Tracfone, Virgin, legacy Sprint) make very heavy use of CDMA, an incompatible technology, with no GSM. All have shut down 2G CDMA; Verizon has announced it will shut down its 3G CDMA network by the end of 2020 (delayed from 2019). Canada's major incumbent telephone companies have abandoned CDMA; they only support 3G (UMTS/WCDMA) now. As CDMA-standard handsets are not required to provide removable SIM cards, a purchase of prepaid service from a US CDMA provider usually requires buying their branded handset.

Mobile subscribers in the USA and Canada must pay airtime for all calls, in or out. (This is not true in Caribbean nations.) Handsets are assigned local, geographic numbers; one may switch from wireline to wireless service and keep the same number. Calling to a mobile telephone therefore costs the same as calling to a landline. A handset taken out of its local home area incurs long-distance fees on incoming calls; this is less problematic on flat-rate plans. A prepaid SIM will not work until "activated" by phone or (with some providers) on-line, as the subscriber must choose a city (which need not be their place of residence) from which to obtain their local inbound number.

AT&T, Verizon, T-Mobile (in the US) and Bell/Telus, Rogers (in Canada) operate national networks, so roaming is usually not an issue within the same country. Taking a Canadian handset into the US (or vice versa) can be an expensive ($1.50/minute) misadventure as, unlike the European Union, there is no legal limit to what providers can charge for roaming. Downloading large amounts of data abroad has cost some users hundreds of dollars or worse.

There are a few small regional carriers; these will incur roaming costs outside their home region and prepaid top-up cards are likely not in stores outside their home coverage area.

North American providers are notorious for flooding the market with branded handsets which are SIM-locked to one carrier on both pre-paid and post-paid services. A common tactic is to advertise an inexpensive (or even "free") handset in large print, while the fine print obligates the subscriber to a credit application for an expensive post-paid mobile subscription which takes years to pay off. Prepaid handsets are widely available at a reasonable initial price, but usually carry a higher per-minute rate and inflated prices for mobile data (a dime a megabyte on low-end Canadian prepaid handsets is not unusual). Most prepaid-cash plans do not permit roaming.

For travellers and infrequent users, prepaid is likely the only viable option. There is a confusing array of brand names; some are major carriers, some are "mobile virtual network operators" (which resell bandwidth on the network of a major carrier, at a lower price), some are merely one of the majors rebranded under another name to give the illusion of competition. Prepaid minutes from one brand won't work with the others, even if they're using the same underlying carrier.

Refills (in the US) or top-ups (in Canada) for prepaid cards are generally available at convenience stores, filling stations, big-box retailers, pharmacies and Canadian post offices. It is often possible to refill using a credit card online. Some store-brand virtual operators (such as Loblaws or Petro-Canada) sell through their own stores (selected locations) or online only. Long distance on basic low-end prepaid plans is expensive ($0.25/minute airtime $0.25/minute or more for a trunk call is typical for the base "prepaid anytime" plans in Canada, while Internet telephony would cost a penny or two for the same call); it may be cheaper to use prepaid long-distance cards for anything more than a town or two away. Some higher plans, particularly in the US, include unmetered domestic long distance at no added per-minute cost or unmetered mobile airtime (often in off-peak hours). There are also extra-cost plans to extend the meagre data allotment on prepaid mobiles. Direct-dial overseas calls (or calls to former 1 809 points in the Caribbean) are expensive on prepaid plans and best avoided.

Billing for calls usually begins when the call is dialled, not when it's actually answered; providers also round call lengths up to the next full minute.

Directory assistance is available at 4-1-1 or 1-area code-555-1212 but is expensive; advertising-supported competitor 1-800-Free411 or websites like 411.ca, 411.info or canada411.com are cheaper alternatives. Automobile association members may obtain mobile roadside assistance by dialling *222 (*CAA or *AAA); some specific services like #TAXI (#8294) will hail the next available cab in much of Canada or the US for a cost of $1.25-$2.

In the US, few retailers sell used phones; independent phone shops which can unlock a phone are rare outside large-city immigrant communities. Factory-unlocked handsets, used handsets and codes to unlock existing handsets may be purchased online.

Prepaid GSM SIM cards are relatively difficult to find outside the stores of US mobile phone providers. T-mobile offers one ($10) at their own shops or online, AT&T offers a SIM-only prepaid package on their website and stores. Another option is buying the least expensive prepaid phone; if you intend to move the SIM card to your own unlocked handset, do not insert the SIM into the phone supplied as (on AT&T "GoPhone") that will lock the SIM into that phone. T-Mobile also offers visitors a specialised 21-day prepaid SIM for $30 which includes 1,000 minutes of calls, 2GB of 4G data, and unlimited SMS.

Some online services will ship prepaid SIMs overseas or ship specialised "travel SIMs" to North American addresses, but typically overcharge badly (for example Telestial or Cellular Abroad).

Asia

• Some providers in China use TD-SCDMA (an incompatible alternative to W-CDMA on 3G UMTS handsets) or TD-LTE (as an alternative to LTE on 4G devices). These standards are rare in other countries.
• For visitors in India, getting a SIM card is very easy and requires copies of passport and a few photograph. A 6 GB 4G data with 3 month calling can be availed for INR 350 (~US$ 5)
• Japan and South Korea have no GSM coverage but have UMTS (3G) coverage, and most modern phones with 3G capability on the local frequencies should be able to roam there (Korea has 2G and 3G CDMA coverage as well as 3G UMTS coverage).
• Japan will generally not allow sale of SIM cards to foreigners on visa waiver or short term visas unless it is data-only; in general, your options are roaming (with a compatible 3G GSM phone), renting a phone, or using a data-only SIM. This can be done at the major airports (Narita, Kansai, probably others) or via delivery to your hotel or business. Expect to pay $1–2 (¥100-200) a day, plus fairly high per-call/per-minute rates. For data-only SIMs, prices vary wildly as some providers charge anywhere from less than ¥5,000 (~US$50) for unlimited data for 7-days to a total of more than ¥10,000 (~US$100) for a SIM and a mere 5 GB of data good for one month so do some research on this before leaving for your trip.
• South Korea will only sell SIM cards to residents. Short term visitors will have to either use roaming or phone rental from an airport. Note that a South Korean resident is allowed to register a few SIMs, so you could use one registered by a friend,
• Visitors to Singapore can buy a SIM card from currency exchange stalls, service centres of the TelCo providers or 7-11 convenience stores. However, they are required to give their passport at the point-of-sale for the service to be activated. A user is allowed to have a maximum 3 Singaporean SIM cards registered to his name at a time.
• In Thailand, the best place to buy a used phone or get one unlocked is the 4th floor of the MBK mall in Bangkok. More than half the floor (nearly a full city block) is small mobile-phone vendors (most selling a mix of used and new), and many will do repairs, unlocks (and those that don't will generally be happy to take your phone to one that does and split the fee.) Expect to bargain hard!
• Major UAE carrier Etisalat has stores in both Dubai Airport(Terminal 1) and Abu Dhabi Airport. Prepaid plans are economical, purchase requires a passport.

Africa

• Egypt likewise won't let tourists buy SIM cards- as tourists would arrive, buy a card, then throw it out after a few weeks, proof of Egyptian citizenship is required to buy them. There is a way to rent cards, but it's a fairly arduous process involving contacting Egyptian phone companies before travelling, and so probably not worth it.

Australia/Oceania

• 3G usually on 900/2100 MHz (Telstra is 850/2100) and 4G on 1800 MHz and 700MHz.
• Virgin, TPG and Exetel are Australian virtual operators reselling bandwidth on Optus or Vodafone networks.

Europe

See also: European Union#Connect

• Although in theory usage of calls and texts in the EU should initially come out of your plan's domestic allowances if you are an EU-based subscriber, there are still a lot of important exceptions and caveats. For instance, telcos that routinely offer large amounts of data at extremely cheap rates or unlimited data in some form may limit how much of it can be used outside the telco's home country. Telcos may also opt not to offer roaming at all for some of their plans or to charge roaming at the pay-as-you-go Eurotariffs in addition to the standard domestic pay-as-you-go rates. These may happen if a user's existing bundle is priced in a way that telcos would otherwise be paying more to their counterparts elsewhere than receiving from the user from that bundle. In these cases, the onus is on the telcos to state these restrictions clearly. As this feature is intended for EU subscribers who travel other parts of the EU only occasionally, to prevent abuse (e.g. because one's existing plan is cheaper than any of those offered by the telcos in a that user's actual country of 'residence'), the EU permits telcos to seek evidence from those who have been using their service outside their home country more than inside within a four-month period. Click here for more information on EU roaming.
• The rules on roaming do not cover calling a foreign number from the SIM's home country. If you are visiting several countries or use the SIM to call home, or European friends, make sure those calls are covered or check the separate price list.
• Registration of SIM cards in Germany is now compulsory before they can be used. If you want to register your SIM at the same time as you purchase it, you need to purchase the SIM directly at a store operated by a telco (click on these for T-mobile, O2, and Vodafone shops) or its appointed partners (click on these links for a list of Lebara's and Lycamobile's partners) and bring your passport with you as registration involves verification of your identity. Although the process may sound daunting, the user does not have to be a German resident to purchase a German SIM card.
• When purchasing a prepaid French SIM card, activation is required. However the retailer does not require a copy of the passport from the user. Instead, the user will have to follow instructions that came with the French SIM card, which either instructs the user to log-on to the provider's website or contact a hotline. These can be purchased at retailers.
• Visitors to Italy are required to produce a passport when purchasing a SIM card in order to have the service activated. In some cases, a photocopy of the passport may be all that is sufficient - this is at the merchant/retailer's discretion. You can purchase prepaid SIM cards at foreign currency stalls and at stores of mobile phone providers.
• You can purchase UK prepaid (known here as "pay as you go") SIM cards at vending machines right before baggage claim in Heathrow Airport. Supermarkets and off-licence stores also sell SIM cards and top-up vouchers. Specialist mobile phone providers such as Lebara, Vectone and Lycamobile offer good rates for frequent overseas calls. At special events and public festivals, representatives of mobile phone providers give SIM cards out for free but you need to top up the required credit. Providers such as GiffGaff only operate online but their SIM cards can occasionally be found at certain events.
• Given the dispute over whether the Crimean Peninsula belongs to Russia or Ukraine, and given Russia's de facto control over the peninsula, most mobile phones that do not have a Russian SIM card will not work on the peninsula.

Satellite phones

Inmarsat satellite telephone deployed after the 2005 Sumatra earthquake in Indonesia.

In remote locations, without cell phone coverage, a satellite phone may be your only option. A satellite phone is not generally a replacement for a cellular phone; they're bulkier and have noticeably more delay than cellular phones, and you have to be outdoors with clear line of sight to the satellite to make a phone call. Satellite phone services are frequently used by maritime transport (including pleasure craft) as well as expeditions who have remote data and voice needs. Your local telephone service provider should be able to give more information about connecting to this service.

Several networks use geostationary satellites, which can cover large portions of the Earth with as little as one satellite, and global coverage with only a handful. In addition to voice calls, these can also provide relatively high bandwidth data connections (perhaps around 60 to 512 kbps, and up to 50 Mbps in some of the newest hardware). Such a system does have disadvantages: there's some delay (around 0.25 seconds, due to the speed of light), and it can be difficult to get line of sight if there are hills or trees in the way. They also cannot provide coverage at the poles north/south of 70-80 degrees latitude. While the services are packaged and provided to consumers by a number of companies, it's more useful to describe the few satellite operators themselves. They are:

• Inmarsat — Global coverage from 13 satellites
• MSAT — North America
• Terrestar — North America
• Thuraya — Their network, using a Thuraya handset, allows roaming from GSM to satellite depending on network availability. Check to see if they have an agreement with your home network. Some networks (for example Vodafone UK) charge a very high rate for incoming calls (£6.00/min). If a lot of calls are to be made, buy a SIM card from a satellite phone provider. Calls on the Thuraya system cost from $0.50-$1.30/min. Thuraya network uses geostationary satellites over Europe, Africa, Asia and the Middle East, so check for coverage in the area you are travelling to. You may have to orient the antenna of the device towards the satellite for best reception.

Two other networks operate satellites in low Earth Orbit. These orbit the Earth every 1½-2 hours using a network of several dozen satellites. Reception on the ground changes rapidly over time, as each satellite is only in view for 5-15 minutes; as they arc across the sky, your signal may be temporarily blocked by obstacles. The network should pass connections to the next satellite, but if your signal is blocked before this can happen it can cause calls to drop. Data speeds are significantly lower at just 2200-9600 bit/s, although upgrades will bring this into the range of 128 kbps or better.

• Globalstar — Globalstar's system is, in theory, capable of covering across most of the continents (but not the polar regions) and some of the oceans, but satellites relay calls directly to ground stations and there are gaps in certain remote areas where there are no nearby stations. Cost is typically $1-1.50/minute plus a monthly subscription; in most countries, Globalstar issues numbers which look to be within the country (so a Canadian might get a Calgary or Smiths Falls geographic number) and its subscribers pay to receive calls.
• Iridium — The only truly global network, Iridium works anywhere with line-of-sight with the sky. Their satellites orbit pole-to-pole, ensuring coverage of every continent and ocean as well as excellent coverage in extreme northern/southern latitudes. Because calls are routed from satellite to satellite until they reach one of the four ground stations, delay is large and fairly variable (around 1 second up to 1.8 seconds). Expect to pay about USD 1.50-2.00/minute for outgoing calls, with only slightly lower rates to call another Iridium phone. Iridium does not sell direct and only sells phones through dealers who may also rent units as well.

For fixed installations in off-the-grid locations, satellite Internet may be adequate to allow Internet telephony. This is a standard way to reach points like Chicken, Alaska or an outfitter's camp in the distant wilds of Labrador; as no local infrastructure exists, a business offering a wi-fi hotspot by necessity feeds directly to a dish.

Satellite phones may be unavailable for purchase or illegal in Saudi Arabia, China, India, Myanmar (formerly Burma), Cuba, Iran, Libya, North Korea, North Sri Lanka, and Syria. They will still function in these areas, however. Some countries require a special permit for using satellite phones within their territory.

Conversely, the Newfoundland government will lend a satellite phone with very limited capability to travellers on the Trans-Labrador Highway through remote regions of Labrador, where this is the only viable means to call for roadside assistance.

Usage

See also: Smartphone apps for travellers

Most mobile phones come with a camera, and are useful for travel photography and video recording. These are usually less capable than a dedicated digital camera or an expensive DSLR (as they lack features like optical zoom or interchangeable lenses), but they offer the advantage of portability as they are small and inconspicuous. There are many smartphone apps useful for travelers.

For video recording or if taking lots of photos, your memory card may run out of space, and it is easy to lose the minuscule modern ones while changing cards in busy areas or off road. Plan ahead so that you can do it in a comfortable environment, or perhaps offload to USB sticks (using a laptop or a suitable adapter), which are easier to handle. Mobile data can be used to upload the recordings, but do your math on storage needs, expenses and upload times with realistic (or worst-case) bandwidth.

In the United States of America and Canada) wireless public alerting (WPA)-compatible 4G LTE telephones can receive emergency alerts from various levels of government to warn of inclement weather, fires, natural disasters, terrorist threats and civil emergencies. Alerts are sent as (seemingly) regular SMS messages in some other countries. These alerts are geo-targeted and cannot be opted-out (assuming the phone is turned on) but there is no charge to receive them.

Stay safe – if you get an "EMERGENCY ALERT/ALERTE D’URGENCE" message, follow its instructions.

See also

• Smartphone apps for travellers