This is a straightforward deal on transatlantic economy awards. Chicago O'Hare to London Heathrow is pricing at 40,000 United MileagePlus miles for travel on April 9, 2026. The taxes and fees come in at just $6, which is notably low for flights into the UK.
For context, economy awards on this route typically run around 60,000 miles through United's dynamic pricing. At 40,000 miles, you're saving roughly 20,000 miles per ticket—meaningful if you're booking for a family. Availability appears solid right now, so you shouldn't have trouble finding seats if you're flexible.
April is a pleasant time to visit London. You'll catch early spring weather, and it falls outside peak summer travel season, which likely explains the lower award pricing. School spring breaks vary, so check your family's calendar before booking.
One practical note: if you don't have United miles on hand, they transfer instantly from Chase Ultimate Rewards at a 1:1 ratio. This could be a reasonable use of a flexible points balance if London is on your list.
How to book
Search and book directly through United's award search tool: https://www.united.com/en/us/book-flight/united-awards/search