Award flights from Chicago O'Hare to London Heathrow are currently available for 40,000 United MileagePlus miles in economy class. Travel dates around April 5, 2026 are showing plenty of availability, and the taxes and fees come in at just $6—unusually low for transatlantic travel to the UK.
This rate sits well below the typical 60,000-mile price tag you'd normally see for economy awards on this route. That 33% discount means you're keeping 20,000 miles in your account for future trips, which could cover a domestic roundtrip or help top off another international booking down the road.
Availability appears solid right now, but spring travel to London tends to attract families during school breaks, so don't wait too long if your dates are firm. April weather in London is mild and the city is less crowded than summer months—a practical choice for families who can travel during that window.
One tip: if you're booking for a family, search for your full party size at once. United's award search will only show results where enough seats are available for everyone, saving you the hassle of piecing together separate bookings.
How to book
Search and book directly through United's award search tool: https://www.united.com/en/us/book-flight/united-awards/search