Most of the people who travel longterm don´t buy roundtrip tickets. Doing this, they would loose a big part of their freedom. Without a fixed plan you have access to all options which might come up to you and you can just “follow the flow”.
When I was traveling in Southamerica, I´ve only bought a ticket to Chile. I had a kind of a plan in my head but it changed almost every day and with every person I´ve met. Only because someone told me how to find incredible cheap inland flight tickets I went down to Patagonia (And I´ve randomly met two Chileans on a house party who bought the same ticket and joined my trip). I went to the Carnaval in Rio de Janeiro, to a concert of Manu Chau in the middle of the jungle, visited a friend in Ecuador and traveled to Colombia,Bolivia and Peru even though that was not planned at all.
Though the law states that onward tickets are required, the immigration officials will very rarely check it when you enter. However, airlines may refuse to allow check-in to destination without an onward ticket, because they are responsible by law to check this details (Because they must pay the bill for your return if your entry was denied).
Most of the airlines hold a 24h reservation for free. If you denied payment, they keep it on hold. Print that page out that shows reservation number and flight/date number and you´re good to go🙂
If that doesn´t work, there are companies which let you “rent” a flight ticket for 48 hours , for example https://bestonwardticket.com/ It costs you $12,00 and it´s totally legal because you are having a valid ticket at your time of arrival. Check the current references of the website before you buy your ticket here.
You also have the option to create a fake ticket with returnflights.net. Be careful with this method, because if you get caught, you´ll have a problem. For 99,999% they won´t check your flight ticket further, you just have to make sure that all details are correct. So make sure you follow these points when you fill out your flight form:
Do not fly back to your country. The person at the check-in counter might be suspicious because return flights with the same air carrier are normally cheaper.
Do not choose the same airline for your onward ticket. They might check it at the check-in counter..
Make sure you enter a valid flight and flight dates/time. Check here for valid flight dates.
Once you printed out your flight ticket. Highlight your name and flight destination with a marker. The person on the check-in counter will appreciate it and will not check further details.
Fill out the form (When entering the amount write e.g. 50.90 and not 50,90), click on Create a Ticket, unpack the folder in Downloads and open the file agent.dll.dm (No Virus, promise 😉 ).
Tadaaa – there´s your ticket! Check all details, print it and travel!