The most common first-time mistakes in Peru are booking Machu Picchu and treks too late, planning too many stops, ignoring altitude on the first days, leaving no buffer before the flight home, and relying on a single payment method. All of them are avoidable with planning done in the right order.
Book the regulated items first, then the flights, then the hotels, and leave slack.
Booking in the wrong order
Some things in Peru have limited capacity and sell out: Machu Picchu entry tickets for popular time slots, train seats, Inca Trail permits and some treks. These should be booked before hotels and before non-refundable flights, because a hotel can usually be found at short notice and a Machu Picchu ticket cannot.
The common error is the reverse: fixing the flights and hotels first, then finding that the day you arrive in Aguas Calientes has no tickets left. In low season this matters less. In the dry season it matters a great deal. See Machu Picchu tickets to understand how the slots work. See Machu Picchu mistakes for the errors that apply to the site itself.
Too much, too fast
The second error is packing too many places into too few days, covered in more detail in too many cities and the real length of five days. A related one is scheduling a demanding day immediately after a flight into the mountains. The first day at altitude should be the lightest, not the most ambitious.
A good test is to count the number of nights in the busiest base. If the answer is one, the plan probably has a move too many. If you are surprised that your route has so few days of sightseeing, check the time lost in transit; the gap between the map and the clock is where most trips go wrong.
No buffer at the end
Domestic flights are delayed or cancelled for weather and other reasons, and roads can be blocked. Arriving in Lima on the same day as the international flight, or even the morning of it, leaves no margin. Keep the last night in Lima, or at least a spare day before the flight, and buy domestic and international flights on a single ticket if you can.
Travel insurance that covers delays, missed connections and medical care, including at altitude and during activities like trekking, is part of the same logic. Read what it covers before relying on it. See travel insurance to understand what to look for.
Money and small practical errors
Cards are accepted in many hotels and restaurants in cities, but small shops, markets, taxis and rural areas often work in cash. Carry some local currency in small notes. Not all cash machines work with every foreign card, and withdrawal limits and fees vary, so bring a second card kept apart from the first. See money for the options.
Other small errors: carrying the passport photocopy only when the original is needed, drinking tap water that is not safe, taking taxis without agreeing the price, packing only for warm weather when the mountains are cold at night, and buying a local SIM or eSIM too late to book things on arrival. For the last two, see scams and SIM cards and eSIMs.
Underestimating the health basics
Three health habits are often ignored. First, water: tap water is not generally safe to drink, and ice and salads in cheap places carry some risk, so ask locally and use bottled or treated water. Second, sun: at altitude the sun is strong even on cool days, and a hat, sunscreen and sunglasses matter more than people expect. Third, medication: bring what you need, with a note from a doctor if it is a controlled item.
Vaccinations and altitude medicines are matters for a doctor or a travel clinic, ideally several weeks before departure. See health and vaccines for general information only. None of this is a reason to worry; it is a reason to prepare, since a day lost to a stomach upset costs as much as a delayed flight.
Believing the schedule
A final mistake is trusting every time on a tour brochure or booking website. Journey times are approximate, and strikes, roadworks and weather change them. The cure is not worry but slack: spare half days, no fixed-time commitments the day after a long transfer, and a habit of checking the plan with your hotel the day before.
The same applies to opening hours and entry rules, which change, so keep some flexibility around them. A trip planned this way is not a more anxious one; it is simply one that is easier to repair when something moves.
Choosing the wrong season for your priorities
Many first-timers choose the dates for convenience, such as school holidays or a leave period, without checking what the season means. In the Andes, the dry months give clear views and firm trails but crowded sites and higher prices, while the rainy months give quieter places with more risk of delay. Neither is wrong, but each suits a different traveller.
Check the dry and rainy seasons before fixing the dates, and if your dates are inflexible, choose the route that suits them. A rainy-season trip with a spare day and good insurance is often better than a dry-season trip with no slack at all.
Frequently asked questions
What should I book first?
Machu Picchu tickets and trains, Inca Trail or trek permits, and the long-distance flights. Hotels can follow.
Do I need cash in Peru?
Yes, in small amounts for markets, taxis and rural areas. Cards work in most city hotels and restaurants.
Is travel insurance really necessary?
It is strongly advised, particularly for altitude, trekking and domestic flights. Check the policy details.
Is it a mistake to fly into Cusco on the first day?
Not necessarily, but it makes the first night harder. Many travellers sleep in the lower Sacred Valley first, or keep the first day in Cusco very light.
What is the most common mistake with Machu Picchu?
Leaving the ticket and train until after the hotels and flights are booked. Capacity is limited, and sold-out dates can force a change to the whole route.
Should I buy a local SIM before I arrive?
An eSIM bought before departure works on arrival, and a physical SIM can be bought at the airport. Either way, plan for connectivity before the first domestic flight.
How much spare time is enough?
One spare day in the second half of the trip and a night in Lima before the international flight is a reasonable minimum. More is better if you travel in the rainy season.