Cheap Transatlantic Flights: Find Fares Under $400 to Europe

The Atlantic crossing is one of the most competitive flight routes on the planet. Dozens of airlines compete for passengers between North America and Europe, and that competition occasionally produces remarkable prices — round trips for under $400, sometimes under $300.

These fares exist. This guide shows you exactly how to find them.

Why Transatlantic Fares Drop So Low

Several forces push transatlantic prices down periodically:

Ultra-low-cost carrier competition: Norse Atlantic, PLAY Airlines, and Condor have entered the transatlantic market with fares that force legacy carriers to respond. When a new carrier launches a route, prices often drop significantly in the first few months.

Shoulder season oversupply: Airlines schedule heavy summer capacity for peak demand. In spring (March–May) and fall (September–November), that capacity doesn't fill as easily. Airlines drop prices to stimulate demand.

Hub competition: Routes between multiple US hubs and the same European city create competitive pressure. New York–London is served by over a dozen airlines. That competition keeps prices lower than routes with fewer options.

Error fares: Occasionally, airlines or OTAs publish fares at prices well below intended. These are rare and last hours, but they produce some of the lowest transatlantic prices ever recorded.

The Cheapest Months to Fly Transatlantic

Based on multi-year fare data, the cheapest months for US–Europe transatlantic flights are:

January–February: Post-holiday lows. The coldest, least desirable weather in Europe creates the lowest demand. Fares can drop 40–50% below summer peaks.

March–early April: Before spring break demand kicks in. Good prices and improving European weather.

October–November: Fall shoulder season. Lower fares than summer with decent weather across most of Europe.

Avoid: June–August (peak summer), Christmas/New Year week, and Thanksgiving week.

Cheapest Routes: US to Europe

Not all transatlantic routes price equally. These consistently offer the lowest fares:

New York (JFK/EWR/JFK) → London (LHR/LGW/STN)

The highest-volume transatlantic corridor. Competition from BA, Virgin Atlantic, Delta, United, American, Norse, and multiple charter operators keeps prices suppressed. Sub-$400 round trips are common in shoulder season.

New York → Dublin or Shannon

Aer Lingus frequently runs promotional fares from New York. Their connections to mainland Europe make Dublin a useful gateway.

Boston → Dublin/Lisbon/Reykjavik

Boston's European routes are underserved by full-service carriers, which creates pressure for promotional pricing. PLAY Airlines serves Reykjavik with connecting service to Europe at very competitive rates.

Chicago (ORD) → Amsterdam/Frankfurt

Lufthansa and United hub competition on Chicago–Frankfurt produces periodic sales. Chicago–Amsterdam via KLM similarly.

Los Angeles → London/Amsterdam/Paris

West Coast transatlantic fares are structurally higher due to distance, but competitive pressure has brought LAX–LHR fares down to $500–600 in shoulder periods, with occasional sub-$500 deals.

Airlines to Watch for Cheap Transatlantic Fares

Norse Atlantic Airways

Launched in 2022, Norse operates 787 Dreamliners on transatlantic routes including New York and Los Angeles to London, Oslo, and other European cities. Their introductory and promotional fares are often the lowest in the market on their routes.

Note: Basic economy fares are extremely basic — carry-on bags cost extra. Price the total including bags before comparing.

PLAY Airlines

Iceland-based PLAY offers connections from multiple US cities through Reykjavik to 30+ European destinations. Their fares are often competitive, and Reykjavik is worth considering as a European destination in itself.

Condor

German leisure carrier operating transatlantic routes from multiple German airports as well as US gateways. Not as well-known as legacy carriers, but frequently priced aggressively.

Level (Iberia Group)

Level operates low-cost transatlantic routes primarily from Barcelona and Paris Orly. US West Coast passengers connecting via Madrid can find competitive fares.

Legacy Carriers on Sale

Don't overlook American, United, Delta, Air France, British Airways, and Lufthansa. They run periodic flash sales and promotional fares, particularly in shoulder season. Their fares include a bag and seat selection in standard economy.

How to Find Sub-$400 Transatlantic Fares

1. Set Price Alerts 3–6 Months Out

Transatlantic fare windows open around 11 months before departure. The best prices tend to appear 3–6 months before travel. Set Yellsy alerts at your target price and let the monitoring run.

2. Use Flexible Date Searches

Use Google Flights' price calendar to see fare variation across an entire month. A shift of 3–5 days from a peak date to a shoulder date can save $200–300.

3. Target Shoulder-Season Travel Dates

Departing on a Tuesday or Wednesday (not Friday or Sunday) within an already shoulder-season month produces the lowest fares.

4. Consider Positioning Flights

If you're near a major hub, driving or taking a train to a hub airport can unlock lower fares. New York fares are typically 15–25% lower than fares from smaller northeastern US airports.

5. Follow Deal Alert Services

Services like Scott's Cheap Flights (now Going), Airfarewatchdog, and SecretFlying curate transatlantic deals. Sign up for email alerts on your home airport.

6. Book Last-Minute Strategically

While this is risky for fixed travel dates, transatlantic carriers do release discounted inventory 2–3 weeks before departure when seats aren't filling. Only viable if your dates are truly flexible.

What to Expect at Ultra-Low Fares

Fares under $400 round trip almost always have trade-offs:

Basic economy restrictions: No seat selection, no free carry-on (on some carriers), no free changes or refunds.

Indirect routing: The cheapest fares often involve a connection. Direct is more convenient but more expensive.

Off-peak timing: Cheap flights usually depart or arrive at inconvenient hours (early morning, late night).

Low-cost carrier experience: Norse, PLAY, and Condor are perfectly safe and comfortable for the price, but the experience differs from a legacy carrier.

If any of these trade-offs are dealbreakers for your trip, budget an extra $100–200 for a more flexible or direct option.

Sample Deal Alert Strategy

Here's a practical workflow:

1. →Decide your 3-month travel window (e.g., September–November)
2. →Set a Yellsy alert on your US airport → London or Paris, target $450 round trip
3. →Also set Google Flights tracking on the same routes for general awareness
4. →Check the price calendar monthly to understand fare trends
5. →When Yellsy fires an alert below your target, book immediately

Transatlantic deals don't last long. Same-day or next-day booking is often necessary.

Conclusion

Cheap transatlantic flights are real — but they reward preparation. The travellers who consistently find sub-$400 round trips aren't lucky. They set alerts months in advance, have flexible dates, and understand which airlines and routes produce the lowest fares.

Set your Yellsy alert today on your home airport to London, Paris, or Lisbon. With a realistic target price and a 3–6 month window, the odds of hitting your number are better than most people realise.