How United MileagePlus miles work and when you can use them
United MileagePlus miles are the currency you earn when you use a United-branded credit card or fly United Airlines. You accumulate them with every purchase on the card and every mile you fly, then redeem them for flights, seat upgrades, hotel stays, car rentals, and other travel rewards. The miles sit in your account until you decide to spend them — there is no expiration date as long as your account remains active.
To claim miles earned from credit card spending, you do not need to do anything. The card issuer (Chase, in the case of most United cards) automatically deposits the miles into your MileagePlus account within one to three billing cycles after your purchase posts. If you are flying United, the miles post to your account within 24 hours of your flight, though it can take longer if you did not provide your MileagePlus number at booking.
Redeeming miles is straightforward: log into your MileagePlus account on United's website or app, search for flights using the "Book with miles" option, select your flight, and complete the booking. You can also call United's reservations line to book by phone, though online booking is faster and shows all available options.
Key Takeaways
- Miles from your United credit card post automatically to your MileagePlus account within one to three billing cycles and never expire as long as your account is active.
- You can redeem miles for flights, seat upgrades, hotel nights, car rentals, and other travel rewards through the United website, app, or by phone.
- Award flight prices vary by route, season, and demand — the same flight can cost different numbers of miles on different days.
- You can combine miles from multiple accounts into one if you have a spouse or family member's MileagePlus number, though this requires both account holders to request the transfer.
- Booking award flights online shows you all available options and lets you compare prices in miles before you commit.
Checking your current mile balance
Your MileagePlus balance appears on your account dashboard as soon as you log in to United.com or the United app. You do not need to take any action to see it — it updates in real time as miles post from flights and credit card purchases.
If you have not logged in before, you will need your MileagePlus number (which came with your card or was assigned when you first flew United) and your password. If you do not have a MileagePlus account yet, you can create one for free on United's website before you use your card for the first time. Linking your new card to an existing account is automatic if you provide your MileagePlus number during the card process.
How to search for and book award flights
Log into United.com or open the United app and select "Book with miles" instead of the standard flight search. Enter your departure city, destination, and travel dates. The search results show all available flights sorted by price in miles, with the cheapest options at the top.
Award prices are not fixed — the same route can cost 25,000 miles one day and 35,000 miles another, depending on how many seats are available and how far in advance you are booking. Booking further ahead usually gives you more options and lower prices. Once you find a flight you want, select it, review the total miles cost and any taxes or fees, and complete the booking. Your miles are deducted from your account when ready.
If you do not see any award flights available on your preferred dates, try searching for nearby dates or different airports. Some routes have limited award availability, especially during peak travel seasons. You can also call United's MileagePlus reservations line at 1-800-575-5555 to book by phone, though the agent will show you the same flights and prices you see online.
Using miles for upgrades and other rewards
Beyond award flights, you can use miles to upgrade a paid ticket to a higher cabin (business or first class), book hotel nights through United's hotel partners, rent a car, or purchase gift cards. These options appear in your MileagePlus account under "Redeem miles."
Upgrade pricing varies by flight and cabin. A short domestic flight might cost 5,000 miles to upgrade to first class, while a long international flight could cost 50,000 or more. You can bid for upgrades after you book a paid ticket, or you can use a fixed number of miles to upgrade at the time of booking. The app and website show you the upgrade price before you confirm.
Hotel and car redemptions work similarly: search for your dates and location, see the mile prices for each option, and book if the price makes sense to you. These are usually less valuable than award flights, so many frequent flyers save their miles for flights instead.
Transferring miles between accounts
You can transfer miles from your account to another person's MileagePlus account, but both account holders must request the transfer together. This is useful if you want to combine miles with a spouse or family member to reach a higher award price.
To initiate a transfer, log into your MileagePlus account, go to "Account settings," and select "Transfer miles." You will need the recipient's MileagePlus number and last name. The recipient must then log into their own account and approve the transfer. Once approved, the miles move when ready and cannot be reversed.
United charges a fee to transfer miles: $0.01 per mile transferred, with a minimum of $25 and a maximum of $100 per transfer. This means transferring 5,000 miles costs $50, and transferring 10,000 miles costs $100. Because of this fee, most people only transfer miles when they are close to booking a specific flight.
What to do if miles do not appear in your account
Miles from credit card purchases usually post within one to three billing cycles. If it has been longer than that, log into your card issuer's website (Chase, for most United cards) and check your recent transactions. If the purchase posted to your card, the miles should follow within a few days.
Miles from flights post within 24 hours if you provided your MileagePlus number at booking. If you did not, you can add the miles manually by logging into your MileagePlus account, going to "Add miles," and entering your confirmation number and last name. United will search their records and credit the miles if the flight is found.
If miles still do not appear after a week, contact United's MileagePlus customer service at 1-800-575-5555 or through the United app. Have your confirmation number (for flights) or your card statement (for purchases) ready. The agent can investigate and manually post miles if there was a system error.
Understanding award flight pricing and availability
United uses a dynamic pricing system, meaning the number of miles required for a flight changes based on demand. A flight from New York to Los Angeles might cost 25,000 miles in January but 50,000 miles in July. This is different from some other airlines that use fixed award prices.
Award availability also varies by route and season. Popular routes during peak travel times (summer, holidays, spring break) often have limited award seats, which drives up the mile price. Less popular routes and off-season travel usually have more availability and lower prices. Booking 2 to 3 months in advance often gives you the best selection and prices.
One-way award flights cost the same as round-trip flights on some routes, so it is worth checking both options. You can also book a round-trip and use only one leg if you change your plans, though you will lose the unused miles.
Frequently Asked Questions
Do my United miles ever expire?
No, as long as your MileagePlus account remains active. Your account stays active as long as you earn or redeem miles at least once every 24 months. If your account becomes inactive, United will close it and you will lose your miles. To keep your account active, you can fly United, use your United credit card, or transfer miles from another account.
Can I book a flight for someone else using my miles?
Yes. When you search for award flights, you can enter a different passenger's name and details. The miles are deducted from your account, but the ticket is issued to the person you name. You do not need to transfer miles to their account first.
What if I want to change or cancel an award flight I booked?
You can change an award flight for free if you book it at least 7 days before departure. Log into your MileagePlus account, find your booking, and select "Change flight." If the new flight costs more miles, you pay the difference. If it costs fewer miles, United credits the difference back to your account. Cancellations are also free, and your miles are refunded in full.
Are there blackout dates for award flights?
United does not have traditional blackout dates, but award availability is limited on popular flights during peak travel times. You can search any date, but you may find few or no award seats available on certain routes during summer, holidays, or weekends. Searching for less popular travel dates usually shows more options.
Can I use miles to book a flight for a group of people?
You can book multiple award flights using your miles, but each passenger needs a separate booking. Search for the flight, enter the first passenger's name, complete the booking, then search again for the next passenger. There is no group booking option through the miles system, but you can call United's reservations line if you want to coordinate multiple bookings at once.