Originally Posted by
Flyer500X
Thanks! Didn’t know if booking a return could lead to some immigration nightmares or penalties by the airline
Potential immigration issues would depend on your passport and the country involved. Check the rules carefully and also look at TIMATIC for your situation to see the rules that airline agents will see when you check in. However, IME with a USA passport, I can't recall that an immigration officer ever looked at or asked about my return transportation and I don't know of any country's rules that would require a RT plane ticket rather than just proof of a ticket (for travel before your visa or entry permit expires) using some mode of transportation to some country that you're eligible to enter.