Although Mexican phone service has improved in the last decade, it’s still sometimes hit-or-miss. If a number doesn’t get through, you may have to redial it more than once. When someone answers (usually “Bueno”) be especially courteous. If your Spanish is rusty, say, “¿Por favor, habla inglés?” (¿POR fah-VOR, AH-blah een-GLAYS?)—“Please, do you speak English?”). If you want to speak to a particular person (such as María), ask, “¿María se encuentra?” (¿mah-REE-ah SAY ayn-koo-AYN-trah?).
Since November 2001, when telephone numbers were standardized, Mexican phones operate pretty much the same as in the United States and Canada. In Oaxaca City , for example, a complete telephone number is generally written like this: 951/514-4709. As in the United States, the “951” denotes the telephone area code, or lada (LAH-dah), and the 514-4709 is the number (except in the case of a calling a cell phone, see below) that you dial locally. If you want to dial this number long distance (larga distancia), first dial “01” (like “1” in the United States), then 951/514-4709. All Mexican telephone numbers, with only three exceptions, begin with a three-digit lada, followed by a seven-digit local number. (The exceptions are Monterrey, Guadalajara, and Mexico City, which have two-digit ladas and eight-digit local numbers. The Mexico City lada is 55; Guadalajara’s is 33; Monterrey’s is 81. (For example, a complete Guadalajara phone number would read 33/6897-2253.)
Although Mexican cellular telephones are as universally used as those in the United States and Canada, at this writing they operate a bit differently. Generally, in order to call a local cellular number, for example, the Oaxaca local number 951/514-4709, you must prefix it with “044.” Thus, in Oaxaca City  and Valley, dial 044-951/514-4709. However, outside of Oaxaca City and the Valley of Oaxaca , for example, in Puerto Escondido , you call a cellular number by first dialing “045.” Thus, from Puerto Escondido calling Oaxaca, simply dial 045-951/514-4709.
In Oaxaca towns and cities, direct long-distance dialing is the rule—from hotels, public phone booths, and efficient private computerized telephone offices. The cheapest, often most convenient, way to call is by buying and using a public telephone Ladatel telephone card (tarjeta telefónica). Buy them in 30-, 50-, and 100-peso denominations at the many outlets—minimarkets, pharmacies, liquor stores—that display the blue and yellow Ladatel sign.
To call Mexico direct from the United States, first dial 011 (for international access), then 52 (Mexico country code), followed by the Mexican area code and local number. For example, from the United States, call a Oaxaca local number such as 514-4709 by dialing 01152-951/514-4709. Again, you must dial cellular phone numbers a bit differently, by entering a “1” before the area code. Thus, if Oaxaca City  local number 514-4709 were a cellular number, from the United States you must dial 01152-1-951/514-4709.
For station-to-station calls to the United States from Mexico, dial 001 plus the U.S. area code and the local number. For example, to call San Diego (area code 619) local number 388-5390, from Mexico, simply dial 001-619/388-5390. For calls to other countries, ask your hotel desk clerk or see the easy-to-follow directions in the local Mexican telephone directory.
By far the cheapest way to call home (about $0.50 per minute) is via one of the many public telephones with your Ladatel phone card.
Beware of certain private “To Call Long Distance to the U.S.A. Collect” (or “by Credit Card”) telephones installed prominently in airports, tourist hotels, and shops. Tariffs on these phones often run as high as $10 per minute (with a three-minute minimum), for a total of $30, whether you talk three minutes or not. Always ask the operator for the rate, and if it’s too high, buy a 30-peso ($3) Ladatel phone card for a (six-minute) call home.
In smaller towns, with no public street telephones, you must often do your long-distance phoning in the larga distancia (local phone office). Typically staffed by a young woman and often connected to a café, the larga distancia becomes an informal community social center as people pass the time waiting for their phone connections.
Mexican correos (post offices) operate similarly, but more slowly and less securely, than most of their counterparts all over the world. Mail services usually include lista de correo (general delivery, address letters “a/c lista de correo”), servicios filatelicas (philatelic services), por avión (airmail), giros (postal money orders), and Mexpost secure and fast delivery service, sometimes from separate Mexpost offices.
Mexican ordinary (non-Mexpost) mail is sadly unreliable and pathetically slow. If, for mailings within Mexico, you must have security, use the efficient, reformed government Mexpost (like U.S. Express Mail) service. For international mailings, check the local Yellow Pages for widely available DHL, Federal Express, or UPS courier service.
Telégrafos (telegraph offices), usually near the post office, send and receive telegramas (telegrams) and giros (money orders). Telecomunicaciones (Telecom), the new high-tech telegraph offices, add computerized telephone and public fax to the available services.
Internet service, including personal email access, has arrived in Oaxaca cities and larger (and even smaller) towns. Internet “cafés” are becoming increasingly common, especially in the Oaxaca City , Huatulco , Puerto Escondido , and Puerto Ángel  resort centers. Online rates run $1–2 per hour.
Mexican electric power is supplied at U.S.-standard 110 volts, 60 cycles. Plugs and sockets are generally two-pronged, nonpolar (like the pre-1970s U.S. ones). Bring adapters if you’re going to use appliances with polar two-pronged or three-pronged plugs. A two-pronged polar plug has different-sized prongs, one of which is too large to plug into an old-fashioned nonpolar socket.
The entire state of Oaxaca and all surrounding states operate on U.S. Central Time, the same as Mexico City and central U.S. states such as Nebraska, Illinois, Tennessee, and Louisiana.