Here’s a simple, often overlooked tip that could seriously enhance your next fast-food experience: ask for a receipt when you order your favorite burgers and fries at McDonald’s.

At first glance, it might seem unnecessary—after all, who really needs a receipt for a quick meal? But surprisingly, this small request can make a big difference in both service and food quality. Why? The answer lies in something called “mystery shoppers”—or as they’re known within McDonald’s, Gapbusters.

The Mystery Shopper Effect

Mystery shoppers are undercover evaluators who visit McDonald’s locations to assess everything from customer service and cleanliness to food quality and accuracy. Their job is to make sure that customers are receiving the best possible experience.According to Adnan, a former McDonald’s employee, staff members are trained to be on the lookout for these anonymous evaluators. One of the telltale signs that someone might be a mystery shopper? They ask for a receipt.

Since employees can’t tell whether you’re a Gapbuster or a regular customer, asking for a receipt often puts them on alert—resulting in:

Better service
Fresher, more accurate food
Greater attention to detail
It’s a subtle but powerful way to boost your odds of receiving top-tier treatment.