I am interested in taking a one-way flight from DC (IAD) to Cancun (CUN) on United. I dont have United miles but I have MR points. I see I can transfer those to the Star Alliance via; Air Canada Aeroplan ANA Mileage Club Singapore KrisFlyer ANA doesnt allow one way award flights. Do either Singapore or Air Canada? I tried to find the points price from IAD to CUN using Singapore miles, but their mileage chart doesnt show Mexico as a zone (because presumably, Singapore air doesnt fly there). In short, I've never intentionally taken advantage of an alliance/partnership to book a flight with miles, and I'm hoping somebody could provide me some guidance. What are my options for a one way (nonstop) flight from IAD to CUN on United and how much would it cost points wise? Id be willing to consider round trip if necessary, but I've currently booked the return leg with southwest at a cool 3k points a ticket. I may just end up booking both legs through southwest, but wanted to check my other options, to burn other miles first.