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Amazing United SEA to LHR Flight Deals

The cheapest flights to Heathrow found within the past 7 days were $639 round trip and $529 one way. Prices and availability subject to change. Additional terms may apply.



FAQs about United Airlines Flights from SEA to LHR

What terminal is United Airlines at Sea-Tac Airport?

As soon as you receive your boarding pass for your United Airlines flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to London (LHR-Heathrow), check if the terminal details are listed on it. If not, get in touch with your carrier. They'll be able to tell you exactly where you'll be flying in and out of.

Are there United Airlines non-stop flights from SEA to LHR?

Unfortunately, there aren't any direct flights between Seattle, WA (SEA-Seattle - Tacoma Intl.) and London (LHR-Heathrow) with United Airlines. Be ready to make a stopover if you need to travel on this particular airline and route.

How long is an United Airlines flight from SEA to LHR?

Your United Airlines flight from SEA to LHR should take around 11 hours and 25 minutes, so it's wise to pack an extra set of clothes and some toiletries for the long journey. If you want to keep restlessness and boredom at bay, toss some books and puzzles in your hand luggage as well.

How many direct and indirect flights does United Airlines fly from SEA to LHR?

You have a good range of options if you're heading from SEA to LHR. You'll find at least 23 United Airlines flights available monthly.

If I am not able to travel due to COVID-19, can I change my booking to a later date?

For more info about changing your flight to London (LHR-Heathrow), please visit our Customer Service Portal.

What is the best day to buy a plane ticket?

This just in! Airfares offered on Tuesdays tend to be the cheapest, according to flight demand on Travelocity in 2019. Wednesday and Friday prices are also good, but you may want to prepare your budget if booking on a Monday, as data shows the start of the week is when prices are generally at their highest.

What are the cheapest days to fly?

Frequent travelers may already know this, but earlier in the week can be the cheapest time to fly. In 2019, flights departing on a Tuesday were generally the cheapest of the week, whereas you may pay a premium for weekend flights when demand is usually high. On average, tickets were most expensive for Saturday departures, so if you need to fly out on a weekend, you might look for deals ahead of time.

How far in advance can you book a flight?

Trying to figure out how early you should book your flight? It's possible to start comparing international airfares on Travelocity up to 12 months in advance. However, it does depend on the carrier as not all airlines release their prices that far out. According to our 2019 flight demand trends, last minute planners can still bag a bargain with some of the cheapest fares appearing 1-2 weeks prior to their travel dates.

How can I save money on airline tickets?

We'll let you in on a secret...You can save big on flights if you mix and match your airlines and fare types. In fact, travelers who booked flights on Travelocity in 2019 saved nearly 50% when their return flights consisted of two different airlines or fare types.

*According to flight demand on Travelocity.com from January to December 2019. Savings are subject to change based on departure location, date and destination.

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*Price based on the lowest price found within past 24 hours and based upon one night stay for two adults over the next thirty days. Prices and availability subject to change. Additional terms may apply.