After any flight touches down, it’s normal for passengers to whip out their phones and let their loved ones know they’ve arrived safely. However, one travel advisor and content creator does something else: She starts her phone’s timer.

Delta has a 20-minute baggage return goal

Kayleigh Zavadil shared a little-known tip buried in Delta’s app. When she lands after flying this specific airline, she times how long it takes her checked items to reach baggage claim.

If her stopwatch crosses the 20-minute mark and she doesn’t see her bag, she knows she just earned 2,500 Delta bonus miles. “My home airport is consistently bad about bags on time so I’ve racked up a ton of miles just by this easy tip.”

Sure enough, under the Delta baggage overview page, there’s a form for its 20-Minute Bag Guarantee.

Now, only SkyMiles members who were already signed up before they travelled can earn the extra 2,500 miles. It’s free to become a member, by the way.

The reimbursement only applies to domestic flights. The official time starts after the doors open.

You’ll need to fill out a form within three business days of the delayed baggage claim. It’s located in the Baggage and Travel Fees section of the app. You can also just Google “Delta 20-minute baggage guarantee” and find the form that way.

How do you prove a baggage delay?

One of Zavadil’s followers posed a great question: how do you prove you didn’t get your bags back within 20 minutes?

“They scan the bags as they put them on the belt so delta already knows!” Zavadil replied. The data doesn’t lie, as they say. If you’re flying Delta anyway, then, you might as well sign up for a chance at some free miles. And if you already have the app and didn’t know about the 2,500 bonus miles, here you go.