Update: Some offers mentioned below are no longer available. View the current offers here.Want to see the latest flight deals as soon as they’re published? Follow The Points Guy on Facebook and Twitter, and subscribe to text message alerts from our deals feed, @tpg_alerts.Airfare deals are typically only available on limited dates. We recommend you use Google Flights to find dates to fly, then book through an online travel agency such as Orbitz or Expedia, which allows you to cancel flights without penalty by 11 p.m. Eastern Time within one day of booking. However, if you’re using The Platinum Card® from American Express, you’ll need to book directly with the airline or through the Amex Travel portal to get 5x MR points. Remember: Fares may disappear quickly, so book right away and take advantage of Orbitz or Expedia’s courtesy cancellation if you’re unable to get the time away from work or family.Break out the beer and get ready to say “cheers!” because Aer Lingus is offering flights to Ireland from under $400 round-trip from various US cities!These deals are a part of the airlines Fourth of July sale that is offering $100 off flights from the US to Ireland from November 1 to December 15. We highlighted them some over the weekend, but if you’ve been wanting to visit Ireland and this deal fits in your plans, be sure to book it ASAP as the sale ends at 6:59pm EST on July 8.There’s more availability from other US cities like Minneapolis (MSP) and Miami (MIA), but these tickets are over $400. If you don’t see your city listed in this deal, be sure to check the Aer Lingus site.Note that these prices are in “saver economy” — which means you will be limited to bringing just a carry-on free of charge. If one bag just won’t do, you’ll have to pay the additional baggage fees as well as to select your seatThe quays in Dublin City, Ireland at dawn with the beautiful sky reflected in the River Liffey.To search, head to Google Flights and enter your origin, destination and stopover cities. Scroll through the calendar function to find dates and prices that work for you. Finally, click through to book directly with the airline or through an OTA like Priceline or Expedia.Airline: Aer LingusRoutes: IAD/PHL/JFK/EWR/BDL/ORD/BOS/SEA/MSP/MIA to DUB/SNNCost: $336+ round-trip in basic economy Travel Dates: November 1-December 15, 2019Pay With: The Platinum Card® from American Express (5x on airfare booked directly with the airline), Citi Prestige Card (5x on airfare), Citi Premier® Card, Chase Sapphire Reserve, American Express® Gold Card (3x on airfare when booked directly with the airline) or Chase Sapphire Preferred Card (2x on travel)Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Here are a few examples of what you can book:Washington DC (IAD) to Dublin (DUB) for $336 round-trip:Philadelphia (PHL) to Dublin (DUB) for $336 round-trip:New York (JFK) to Shannon (SNN) for $345 round-trip:New York (EWR) to Dublin (DUB) for $346 round-trip:Hartford (BDL) to Dublin (DUB) for $361 round-trip:Chicago (ORD) to Dublin (DUB) for $376 round-trip:Boston (BOS) to Dublin (DUB) for $381 round-trip:Seattle (SEA) to Dublin (DUB) for $396 round-trip:Maximize Your PurchaseDon’t forget to use a credit card that earns additional points on airfare purchases, such as The Platinum Card® from American Express (5x on flights booked directly with airlines or American Express Travel), Citi Prestige Card (5x on airfare), Chase Sapphire Reserve, American Express® Gold Card, Citi Premier® Card (3x on airfare) or the Chase Sapphire Preferred Card (2x on all travel purchases). Check out this post for more on maximizing airfare purchases.