It is totally possible to travel for free — you just have to have the right strategy and the right rewards program.

For a few savvy travelers, circumnavigating the world isn’t just a pipe dream. Ben Schlappig is one such traveler: a man who has figured out how to fly anywhere, anytime, all without spending a dime.

The secret to this glamorous lifestyle? Frequent flyer miles or vacation miles. Even if you aren’t looking to hop on board a plane every day, traveling for free is still entirely possible for the part-time jet setter.

What Are Vacation Miles?

Vacation miles — otherwise known as airline miles, travel points, or frequent flyer miles — are loyalty rewards available through various credit card programs and/or airlines. Generally speaking, the more you fly or spend on your card, the more you earn. The word ‘miles’ can be a bit misleading, as miles don’t equate to the actual number of miles you travel when flying. Instead, the ‘miles’ act as a point system. Once you accrue a certain number of them, you can turn those points into free airfare.

For instance, the Delta Skymiles program allows members to redeem a free one-way ticket after 10,000 miles, or the equivalent of two round-trip, coast-to-coast flights. Certain credit cards offer point bonuses when members sign up and spend a certain amount, like the Capital One Venture Rewards card, which gives users 40,000 bonus miles after they spend $3,000.

How Do You Rack Them Up?

There are two basic types of vacation mile programs: airline loyalty programs and credit card rewards. Almost every airline has their own version of an airline miles loyalty program. These programs are free to use, and the miles accrued generally do not expire as long as the account is still in use. Some programs even allow frequent flyers to redeem miles from flights taken before they signed up for the rewards. The grace period can span anywhere between three months and a year, and while going through all of your old tickets may seem like a pain, the miles add up fast.

Finding the right credit card miles program can prove a bit more difficult, as the programs are generally a bit less straightforward. For most cards, members earn points that they can then spend on airline miles. The returns vary greatly between cards, and it’s important to research which cards offer the most advantageous terms — from annual fees to cancellation fine print — before jumping in. Credit card rewards tend to offer more flexibility than airline loyalty programs because members can redeem their points with multiple airlines.

There are a number of other ways to accrue airline miles that don’t involve credit cards or even getting on a plane. For example, some airlines give a bonus to members who shop at participating retailers, like Target and Best Buy.

Getting the Most from Your Miles

When it comes to spending your miles, the short answer is: head to your rewards program’s website, enter your account number, and book your ticket. Like so many things in life, however, the simple answer is rarely the full story. Airlines only allocate a certain number of seats per flight to frequent flyers, and blackout dates will keep many members from flying during holidays and other heavy travel days. Also, it’s important to keep in mind that taxes and fees are not covered when using your miles. So, the flight may still cost some money out of pocket.

The biggest key to using your miles efficiently is having a plan in mind long before you actually use them. While not impossible, finding last-minute seats to the destination of your choice can be difficult, especially if you want to use your rewards points to fly to popular vacation destinations. With that information in mind, book your flights as early as possible, and be flexible. Flying virtually for free comes with tradeoffs, and going with the flow is essential if you want to make the most of your miles.