$705 Cheap TAP Portugal flights London (LHR) to Washington (IAD)

You'll discover affordable round-trip TAP Portugal flights from $549 from LHR to IAD by organizing your results from "Price (lowest to highest)" on Expedia. Or look for deals from $705 for a one-way trip.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Search for TAP Portugal flights from LHR to IAD about one month before you want to go. The most affordable time to reserve an international flight is generally 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of fare class or itinerary, the best day to book international airfare is usually Sunday. Friday can be the most expensive. Passengers who book on a Sunday can save 17% on average compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

Sort your results by "Early Morning" and "Morning" to browse the earliest departures from LHR to IAD. Heading off early means you're 20% less likely to experience cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.