The main language spoken is Spanish.
The unit of currency in Peru is the "Nuevo Sol" (S/.). U. S. dollars are widely accepted in hotels, restaurants, and shops. There are several money exchange shops, as well as, banks to exchange currency. Cash machines (ATMs) are in all major cities and major airports, and dispense your choice of either U.S. dollars or soles. Screen instructions are in English and Spanish.
Many banks/businesses/shop owners will not accept banknotes that are not in good condition—bills that have small tears, that have been written on, or are simply well worn. Do not accept bills that are torn or taped, as it will be difficult to pass them on.
Telephones, internet, and fax machines are available in the cities. If calling from Peru to other countries, you will need to dial 00 then the country code, plus the area code of city you are calling. To call Peru, the country code is 51 and the Cusco city code is 84. If you need a calling card, you can use 'HOLA PERU' or go to one of the many 'locutorios' (a private telephone booth and an operator to help you).
You may want to rent a cell phone in Peru.
Electricity in Peru (and at the lodges) is 220 volts. Some hotels have both 110 and 220 electrical outlets. Most electrical outlets in Peru accept the two-prong, flat plugs used in North America. Please bring your own adapters/converters to use while on the trek, as the lodges have a limited supply.