Planning on visiting Japan mid to late October 2023 flying out of EWR Newark, NJ. We have United miles we may want to use towards cost of flight. We do prefer business class but do not have enough miles to cover it all. I see there are some Star Alliance options such as Air Canada which seems to have the lowest price right now, can I use United miles on Air Canada?

I also see from LAX there is Singapore airlines so we can make our way to LAX then onto Singapore but not sure how feasible this is.

First time visiting Japan and can either plan round trip Tokyo or into Tokyo and out of Osaka. As to which airport in Tokyo we are not picky, simply trying to find the best option for us.
Any guidance would be appreciate it.

You can't use United miles on Air Canada's website, but you can use them for partner flight (including AC) mileage purchases if there is award availability via united.com. How many United miles do you have, how many people are flying, and how flexible are you with timing?

Just to emphasise. You can't look at awards on Air Canada (priced in THEIR miles/points ) and pay with United miles. (Think of them as different currencies!) You CAN, as A Little Cow said, use United miles to purchase AC flights... but that must be through United. I do not know if United has a part miles/part cash payment option but if you don't have enough miles alone to redeem flights that might be worth checking. OR perhaps (assuming it is TWO seats you want) look at ONE award and one paid?

Thank you. We each have 120K miles on United. We are two people.

In business from EWR to Tokyo using United miles, it is 88,000 miles each way for Air Canada (there is good availability right now but you may need to leave from LGA or JFK � search NYC code) or generally 175,000 miles direct from Newark to Tokyo (also good avail if you�re flexible) on a United operated flight. ANA has low availability right now.

Thank you. May I ask which dates you searched as I am not fining the 88,000 miles