7 Secrets of Ultralow Airfares

Only Fly on Tuesdays, Wednesdays, and Saturdays

This is a guarantee: The same route, same aircraft, same airline, same everything will cost you more if you depart on a Monday than if you depart on a Tuesday. Why? Because Monday is a peak travel day when most people, including business travelers, need to fly. Tuesday is far less busy. Wednesdays and Saturdays are equally inexpensive; Thursdays, Fridays, and Sundays are equally pricey.

The basic rule is that if you fly on Tuesday, Wednesday, or Saturday, you will save money. That's why I always advise people to schedule their vacations from, say, Tuesday to Tuesday rather than Sunday to Sunday. It's supply and demand. Fly when other people aren't likely to fly and you're going to pay less.

Don't Fly in the Afternoon

In addition to avoiding flights on Mondays, Thursdays, Fridays, and Sundays, you should also cast a wary eye toward afternoon departures. This is the travel industry's version of rush hour. The skies are congested, delays are common, and fares are highest because it's when most people want to fly. To avoid high fares and delays, always look for the earliest possible departure.

Know Your Blackout Dates

It's critical to know which airlines are offering sales and for which time periods and blackout dates, in order to gauge how to find the lowest fares. Nearly every week, the major U.S. airlines launch competing promotions. Be sure to read the fine print within these promotions, and you'll find a wealth of useful information, such as whether or not you'll need to spend at least one Saturday night at your destination or return within 30 days.

As I type this, four domestic airlines (Southwest, Delta, American, and United) are currently offering sales. Each airline's route network and hub airports are different, yet their sale restrictions are strikingly similar: The purchase date is the same, the blackout dates are similar, et cetera. When you start searching for fares within these restrictions, you will almost certainly find a cheaper flight than if you take a shot in the dark.

Most sales end by Thursday or Friday in a given week, so avoid booking on a Saturday or Sunday. Many airlines pull their discounted airfares ahead of the weekend shopping period, only to offer them again by the middle of the following week.

Take a Connecting Flight

I am not advocating the controversial practice of hidden-city ticketing, in which you buy a ticket that connects in your end destination and do not take the continuing flight. This is against virtually every airline's rules of carriage. But you sometimes can save money simply by booking a flight with a connection rather than a direct or nonstop route. Connecting flights take longer (at least two additional hours), but if you're looking for absolute dollar savings, you may find it with this strategy. (Caveat: Connecting flights can occasionally increase the total price because there are more airport fees.)

Book a One-Way Flight

Here's a tip that may save you money on a complicated or long-term trip: Many airlines drastically increase fares for stays longer than 30 days, so if you're planning a long stay you may do better booking a one-way flight rather than a round-trip. It used to be true that one-way fares were not the equivalent of 50 percent of a round-trip fare, but that's no longer the case. Many major U.S. carriers (and some international airlines) today sell one-way fares for half of the cost of the lowest-priced round-trip airfare.

Get a Refund on a Nonrefundable Fare

Nonrefundable flights are generally the least expensive because they come with a steep penalty for changes or cancellation. But here's a helpful little secret: Nonrefundable flights actually are refundable, without penalty, for 24 hours after you book. They are also fully refundable if the scheduled flight is delayed or canceled or if the flight's schedule is dramatically altered after you book. The biggest takeaway, though, should be that 24-hour window. See a nonrefundable fare that looks good? Book it—but don't stop looking for something better until 24 hours later.

Know Your International Gateways

When flying overseas, it's important to know your gateway airports. In Europe, for example, Dublin, Amsterdam, Frankfurt, Madrid, London, and Vienna are served by major airlines from both sides of the Atlantic, which in turn generates more price competition.

Another tip is to learn which international carriers fly directly from your home airport to their home country. For international trips, I usually depart from Boston, which offers great prices to Ireland because it's served by Aer Lingus. I see similarly cheap flights from Boston to the Azores offered by SATA International (known as Azores Express in the U.S.) and to Iceland offered by Icelandair and Wow Air, again because of direct flights to each carrier's home country.