Round trip required?

Coming down Saturday On a 1 way ticket. Didn't make a return reservation due to an Easter "glitch", so return is a little bit up in the air. But planning mid to late April. A friend advised me that a round trip ticket is required before an airline will allow you to travel. Correct or not?

Incorrect. At least for México. I have heard of other countries that require a round-trip ticket such as Fiji but you would have to verify this information. I routinely bomb down to Mexico with one way tickets.

In my experience it's not so much the country that may require...it's the airline.
it's definitely a consideration when I fly to Thailand.
It's never been an issue when I have flown into Mexico on a one-way ticket.
But you never know when you might run into the check in agent who may or may not know the 'rules'.
it's good to know about:
onward ticket.com