In some countries you can make very cheap unlimited local calls.
You may find there are courtesy phones available at airports and similar places for making local calls for a taxi or similar traveller services. Look out for these as you may not need to use a pay phone.
US FCC regulations require pay phone providers be reimbursed for toll-free calls by the toll-free number provider, so additional minutes or a small surcharge may be deducted when using your card from a pay phone.
Now there are pin less phone cards from several vendors: you register one phone number (for example your cell phone number) and add funds to your number when balance is low.
Usually there are charges for received faxes.
There are two main ways you can use a mobile (cell) phone while travelling overseas.
# Take your existing phone and SIM card, and roam onto a foreign network (Roaming) # Purchase a SIM card at your destination, and either use your own phone or purchase/rent one.
Using your phone in places other than its "home area" is called '''roaming''' and the price varies depending on your provider and the what part of the world you're in. While roaming is convenient, charges can be very expensive, and are unlikely to be included in any plan you are on. You will be charged for receiving calls even if this is not the normal practice of your carrier in your country. Calls to your home country are international calls while roaming. A call made from the country you are roaming to will still be an international call to the person making the call and you will incur roaming charges for receiving it. Check with your home carrier to find out what the rates are beforehand, or you may unsuspectingly be making a USD $5 per minute phone call. Take care with voicemail and diversions. If your phone is on, you can incur roaming costs to receive a call that gets diverted to voicemail, and international costs to divert your call to your home voicemail, and international costs to retrieve the voicemail.
Consider using '''SMS''' (short messaging service) as a cheap alternative to making per-minute phone calls. These text messages can be sent between phones, with up to 160 characters per message. While SMS messages can be more expensive when overseas (from USD $0.30 to $1 each), they are cheaper than international calls and can be very useful for keeping costs down. Sometimes receiving them can be free.
There are two things to check, before roaming to another country.
# Is your phone the correct type and can it communicate on the frequencies required by the foreign network?
# Does your carrier have roaming agreements with the country you are visiting, and are you on a plan permitted to roam to another country?
The most widely used cell phone standard in the world is GSM. If your phone is a GSM phone, it is likely to compatible with carriers in other countries. However, if your phone type is CDMA it is unlikely to roam.
Next you need need to check that your phone operates on the correct frequencies for your destination.
GSM phones operate on several different frequencies.
Many lower-end phones are "dual-band," in that they work only on the two frequency bands most commonly used in the country of their origin, and will not work at all in countries that use only the other two bands. Some phones are tri-band, which will cover quite a bit more of the world by adding one of the two foreign bands; the best phones for global usage are '''quad-band phones''' which will '''work on all GSM frequencies'''. The most widely used frequency is 900 MHz. A 900MHz phone (all early GSM phones were 900MHz only) will work in most countries (apart from U.S. or Canada) that have the GSM system.
In summary, if you want a single phone that can be used in ''most places'' in the world with the ''greatest amount of flexibility'', then what you want is an '''unlocked quad-band GSM phone with 3G'''.
Another advanced feature (depending on your carrier) is '''callback service''' which allows you to send a request to your home carrier to ring your phone and connect to someone in your home market, thereby keeping costs low. For example, Hong Kong carrier 3 allows its users to dial special code while internationally roaming which will connect to local Hong Kong numbers at a lower rate than direct dialing. This command typically looks like: "**130*<phonenum>#" and the caller waits for a call back, initiated from Hong Kong. Mainland China also has this service, except the code is "**139*86<areacode><phonenum>#. Other services require a phone call to a special number before the system will call you back. Most non-American mobile providers do not charge for incoming calls, and callback services take advantage of that to help keep your costs low. [http://www.kallback.com KallBack] is a well-known callback service provider.
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 check what frequencies the roaming carrier uses against the capabilities of your phone.
Check your plan allows international roaming. It may need to be enabled, which is must easier to accomplish before you leave home. Some pre-paid plans do not permit any form of international roaming, or may limit the networks that you can roam to.
As an alternative to roaming, local '''pre-paid SIM cards''' are a godsend. The SIM "chip" in GSM phones can be swapped out effectively changing the carrier and phone number of the phone. Most countries sell prepaid SIM cards that you can buy for cash, quickly establishing a new phone number and credit for making calls. No account setup, credit card numbers or bank accounts. Passports or IDs are often necessary (to reduce use of phones by criminals). To add credit to these SIM cards, you can buy "top up" or "add value" cards from newsstands, telephone stores or convenience stores.
Some countries even have a specific SIM card product, exclusively marketed to visitors.
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.
You also need to ensure that it is '''unlocked?''' GSM phones have a SIM card inside of them which provides the "identity" for the phone, including its phone number and cell phone carrier. Some providers "lock" the phone to their service if you purchased the phone from them, which prevents you from switching to another carrier by replacing the SIM card. This is arguably good business sense from the provider's perspective.
To install a new SIM card you will have to make sure your phone is "unlocked." Your provider may provide the unlock code after a certain time period or after paying a certain amount or otherwise for an unlocking fee. There are plenty of resources around the Internet that will help you unlock phones for free or for a small fee (about USD $5), or you may be able to find local phone-whizzes in your own hometown or at your destination that can do it for you on-the-spot for a price. Some brands of phones are easier to unlock than others. For instance, older Nokia phones can be unlocked with a simple code and you can do it yourself, while Motorola or Sony Ericcson 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 just buy an unlocked phone in the first place. In some countries — for example China — phones are never locked. Various web sites and some shops in Western countries also sell unlocked phones, albeit usually at somewhat higher prices than the "deals" you can get by signing a contract for a service and taking a locked phone.
Cheap low-end phones locked to a carrier at your destination are often obtainable.
Charges vary by country/carrier, but per-minute costs for voice calls are often the best option for folks needing local calling service. The SIM card and phone number are usually valid for a month or two (sometimes up to 12 month), staying active as long as you "top up" the card with more credit. It is quite possible to save more than the cost of a local SIM card on your first call.
For example: In Malaysia, with a prepaid SIM card from Maxis/Hotlink, incoming calls are free, while outgoing calls are charged in 30-second blocks of time at around US $0.15/minute for local calls, or US $0.70/minute for longer-distance calls across the country. By the end of 2005, the cost of prepaid SIM packs had dropped significantly. Internation rates are also low, thus getting a SIM pack makes sense for folks who will be staying at least a week, or expect to do lots of calling locally for business, or want to be reached by locals at local rates.
Because of the trend for regularly upgrading mobile phones, many people will have an old phone that is perfectly functional. It is worth taking this as well as your current phone. This will allow you to keep your existing number active whilst travelling but you can take advantage of the reduced costs with a local SIM card. If someone calls on your normal home number call them back from the local SIM, it will be cheaper! You could pay as much as US $3.00/minute to receive a call on your home number whilst roaming, whereas, to call back using a local SIM may cost US $0.50/minute. Make sure the old phone has the required frequency band(s) as mentioned above.
For people who travel through different countries a so called [http://www.prepaidgsm.net/en/international.html international card] may be an interesting alternative. Such SIM cards 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 UK or smaller European countries. There are many different ones available, so shop around. The cards sold at airports may not be the cheapest.
You can often rent a local cell 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 after only a week or so of rental. Compare the prices.
Please see the ''Contact'' section of the destination country article for information on communications specific to one country.
Some older phones need to select or allow a roaming change from a user menu. Bring your manual or make sure you know how to access the menus. An explanation and listing of who is on what system and frequency, including old systems is at [http://www.my-siemens.com/MySiemens/Files/Addon/an/us/se/worldphone.pdf Siemens].
For truly global walk-and-talk roaming you are going to need an Iridium 9505a handset. Unlike other satellite systems you can use Iridium everywhere so long as you have line-of-site with the sky. Iridium works on all land masses and oceans including both poles. For political reasons service is not offered in: Myanmar (formerly Burma), Cuba, Iran, Libya, North Korea, North Sri Lanka (temporarily opened for disaster relief), and Syria. Expect to pay about $1.50 minute for outgoing calls though this can be as low as $.99/minute to call another Iridium phone. Iridium does not sell direct and only sells phones through [http://www.telestial.com/view_product.php?PRODUCT_ID=SPHN-IR95 dealers] who may also [http://www.telestial.com/rentals_SP01.php rent] units as well.
Some other sites to investigate:
Remember, though, that satellite phones may be illegal in Saudi Arabia.
Internet phones are based on the open [http://en.wikipedia.org/wiki/Session_Initiation_Protocol SIP] protocol and various proprietary protocols. SIP phones are implemented as a program running on a computer, an adaptor that lets you connect an ordinary PSTN phone to the internet or a phone that can make internet calls. Proprietary protocols are only implemented in software, i.e. you have to bring a computer or PDA when traveling.
If your mobile has a WiFi radio built-in, it may be possible to make VoIP calls (depending on the software on your phone). Certain software (e.g. Fring) can be used to connect to existing VoIP protocols such as MSN and Skype, and allow you to instant message or make voice calls with other users (video calls are unsupported).
If you travel with a laptop or PDA, you just need a network connection, a 5 dollar headset, some Voice over IP software, and an account with an IP->PSTN provider. Popular software SIP phones [http://www.xten.com/index.php?menu=products&smenu=download X-lite] for Mac and Windows and KPhone for Linux. Software for proprietary protocols are provided by internet phone companies.
You can bring an SIP adaptor that will let a normal phone work with a wired network. It will not work on wireless networks unless you also bring an access point. The [http://www.grandstream.com/y-286.htm Handytone 286] is small and works with 110-240V.
Wireless phones such as the [http://www.zyxel.com/product/P2000W.php Zyxel P2000W AKA WSIP] can make and receive calls from wireless networks. But it does not work on networks that expect users to accept a policy in a browser.
In some countries, internet telephony can be blocked. This is usually done to protect the revenues of national phone companies. Until recently, Etisalat, the state-owned telecommunications provider of the United Arab Emirates allowed connections to Skype network, blocking only the company website in order to prevent users from adding credit to their accounts to make PSTN calls. The restrictions were later reinforced by blocking access to Skype network entirely. However, Skype is still accessible from some hotels that provide access through 'TheWayOut' wifi service.
Because calls are routed over the internet you do not need to use a phone company located where you live or where you travel. Often you have to separately buy a global number, that allow PSTN phones to call you. It does make a difference where the number is from for people calling you. Services such as [http://www.ipkall.com/ IPKall] allows you to have numbers in different parts of the world for free.
Some Internet phone companies (E.g. Musimi) will forward voicemail messages as email attachment so you can listen to them at internet cafes when traveling.
[http://www.lonelyplanet.ekit.com/ Lonely planets Ekit] even allow people to leave messages on your voicemail for free using a toll-free number and you can then retrieve them from the Ekit home page or pay to listen to them from a phone.