Keep cash on you
Peru has a developing economy, which can mean a variety of things, but it adds a minor complication for visitors. It is important to understand that credit cards are not widely accepted in this country. Cash is king in this country, and while things have improved slightly, it is still necessary to withdraw money and carry cash with you at all times.
How you decide to carry your money in Peru depends on factors such as the duration of your trip and your style of travel. It’s not a great idea to carry large amounts of cash in Peru (dollars or nuevos soles), but it’s certainly a viable option for short visits (up to a week). Otherwise, you can simply withdraw money when needed from ATMs all over Peru; Visa is the most widely accepted debit or credit card in Peru; there will be fees associated with each withdrawal. Traveler’s checks are also an option (ideally in U.S. dollars or Euros) but may be hard to cash in small towns and villages, and the exchange rate can be poor.