Can I just show up and camp?

No. Rangers strictly enforce booking requirements. You will be denied entry to the trails if you do not have confirmed camping reservations for every night of your trek.

Is there a best time of day to book?

The booking portals often crash when they first go live. Be online at the exact minute they open, usually set to local Chilean time.

Does it matter if I fly into Chile or Argentina?

It matters for the logistics. Flying into Puerto Natales (Chile) is closest for Torres del Paine, but many people fly into El Calafate (Argentina) and take a 5-hour bus across the border.

Booking a Patagonia Trek: Timing Your Reservation

Book your Patagonia trek at least 6 to 9 months in advance. Campsites and refugios in parks like Torres del Paine sell out almost immediately once booking portals open for the season.

Check the opening dates. Park operators typically open reservation systems between May and July for the upcoming southern hemisphere summer season (October–April). Check the websites of Las Torres (formerly Fantastico Sur) and Vertice Patagonia frequently starting in April.
Map your route first. Decide if you are doing the W Trek or the O Circuit. The O Circuit requires specific campsites that reach capacity faster than the W. You cannot book your flights until you have secured these site reservations.
Secure campsites before flights. Never book your international flight to Puerto Natales or Punta Arenas until you have confirmed dates for your campsites. If you can't find continuous space for the O Circuit, you may have to pivot to a shorter W Trek itinerary.
Use a consolidator if you are late. If you are inside the 6-month window and everything looks booked, check third-party trekking agencies. They often hold blocks of space for guided groups and sometimes have last-minute openings for solo hikers.

Can I just show up and camp?: No. Rangers strictly enforce booking requirements. You will be denied entry to the trails if you do not have confirmed camping reservations for every night of your trek.
Is there a best time of day to book?: The booking portals often crash when they first go live. Be online at the exact minute they open, usually set to local Chilean time.
Does it matter if I fly into Chile or Argentina?: It matters for the logistics. Flying into Puerto Natales (Chile) is closest for Torres del Paine, but many people fly into El Calafate (Argentina) and take a 5-hour bus across the border.