00 ( zero zero ) is the International Access (Dial) Code used to call overseas from 'within' Peru. 

51 ( five one ) is the International Country (Calling) Code for Peru.

To call cellular phones in Peru you only need to add the 51 number, not the city code.

Then you will need to add the city code, being the most important :

  • Lima: 1
  • Cusco, Aguas Calientes, Urubamba, Sacred Valley : 84
  • Puno,Juliaca : 51
  • Arequipa : 54

To make national phone call within Peru you need to dial : 0 and then the city code

To Make an International phone call you need to dial : 00 and then the country code

To obtain phone number information  dial : 103

Emergency phone number is :  105  (not 911)

In April 2008, the dialing pattern changed for cellular phones in Peru.  All cell phone numbers are now 9 digits, and always start with a 9 as the first digit.  No city code is required to be added to any cellular phone number.

If you have an unlocked GSM cell phone that includes the 850mhz and/or 1900mhz bands, you can purchase a prepaid SIM card upon arrival to use in your phone.  You will get a local 9-digit cell phone number and can immediately make and receive calls while in Peru.  Movistar has superior service and is in the 850mhz band. Claro has acceptable service, and is in the 1900mhz band. As of March 2009, you can purchase a SIM card for 15 Soles at many vendors, including the big department stores Ripley and Saga Falabella.  All incoming calls and text messages to cell phones in Peru are free. Cell phone rates have come down a lot in the last year, and now both Claro and Movistar now charge 50 centimos per minute for outgoing local calls for newly purchased phones and/or SIM cards.



Update from An0nyMs (February, 2013): This advice all still seems to be true. (Please read the note about putting a 9 before phone numbers.  It was necessary even when calling another Peruvian phone number in the Sacred Valley.  For instance, a friend's phone number started with 984, not 84.  Arequipa "land line" numbers still start with 54. But don't worry: simply ask people how to call them -- then try it yourself from your phone.)  An unlocked U.S. T-Mobile phone worked fine. (T-Mobile will give you the unlock code!  Just ask.)  Yo bought a Movistar SIM for 15 soles in Cusco; after more than a week of using it on and off, I still have a balance of 10 soles.

Oh, and to check the balance remaining, Movstar's website tells you to dial 123, then option 1, then option 1.  It seemed easier to see the number on the screen.  By sending a text to 600 with the letter S in the body, they texted back with a message saying: "Otros moviles y fijos: S/. 12.52."  (That means the balance at the time was 12.52 soles.  At 49 centimos per minute, that's quite a few calls!)

According to T-Mobile, Movistar has 3G service, and Claro has 2G service.  Unless you're using data, the difference won't matter to you. But the coverage band (850 MHz vs. 1900 MHz) might.  Friends  had phones on both carriers; they (at their home, at least) got much better signal from Movistar.  If you'll be staying in a particular area, you might ask around.  Or get SIM cards (chips, pronounced "cheeps") from both companies.