From arriving at the airport too late to forgetting your passport, we’ve all made our fair share of mistakes while traveling. But as many start to plan their spring break warm-weather getaways, experts say some mistakes could cost you more than others.

Now is a great time to start planning a spring break trip, but depending on where you’re looking to go, the window is quickly closing, according to travel app Hopper. It’s advised to book international trips at least eight to 10 weeks before departure, while it’s typically three to six weeks for domestic flights.

The most popular destinations this year include Las Vegas, Orlando, Miami, Cancun, San Juan and Punta Cana, according to Hopper’s data, which also forecasts a 12% increase in airfare to those destinations compared to last year.

Experts say three common mistakes could cost you even more.

Being inflexible

Generally, flexibility can go a long way when planning a trip and can often lead to significant savings, Clint Henderson with the travel website ThePointsGuy.com says. Traveling midweek can unlock deals.

“If you’re traveling on a Tuesday or Wednesday, prices are going to be cheaper,” he said. “If you can add flexibility to location or time of arrival window of two or three days on either side, you’re going to unlock a lot of deals, not just with points, but with cash fares, too.”

Using Google Flights’ “Explore” tool, you can easily find flexible dates. Just enter your departure city, price range and desired trip length.

Not checking your passport

This mistake could ruin your vacation. Don’t assume you’re in the clear just because your passport isn’t expired, Henderson warns. A traveler went viral on TikTok when they were turned away at the airport because their passport was due to expire in five months.

The fact is, many countries require your passport to be valid for at least six months beyond the dates of your trip, according to the U.S. Department of State.

“That includes a lot of countries that you want to go to, most likely,” Henderson said. “The good news is Canada and Mexico are a little more loose. It just has to expire after you get back from your trip, but that’s a big one for people.”

Forgetting your rights to a refund

While a flight delay or cancelation can derail a trip, new federal refund regulations in effect for U.S. airlines should make getting a refund easier and faster.

Passengers who opt not to rebook are now entitled to an automatic refund if their flight is significantly delayed or canceled. The Department of Transportation rule requiring airlines to issue refunds — not vouchers — went into effect in October.

The new rule mandates airlines issue refunds without passengers needing to ask. Refunds must be issued within seven business days if the passenger paid by credit card and within 20 calendar days for other forms of payment.

The new refund rules also apply to ticket upgrades, baggage fees, or other extras like Wi-Fi.

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