10 Costco Facts Employees Know That Most Shoppers Don't

Ever wondered what really goes on behind the scenes at your local Costco? Maybe you're curious about how the store's inventory is laid out, want to know how the checkout lines work, or have a few burning questions about the retailer's iconic rotisserie chicken. Thankfully, we did the work for you and put together a list of 10 facts about Costco that just might come as a surprise.

To find these lesser-known tidbits about Costco's warehouses, we checked social media confessions from former and current employees, especially in discussion forums like Reddit. A few of these facts are even hidden on Costco's website or in its employee job descriptions, which is why you might not be as familiar with them. Regardless of how often you visit your local warehouse, we're pretty confident you'll find some new information on this list. You might even be able to use some of it to your advantage during your next trip inside the store.

One of Costco's most famous products — besides its $1.50 food court hot dog (which is an even better deal now than when it first debuted) — is undeniably the Kirkland Signature Rotisserie Chicken. Made in-house by Costco employees, it's served up warm, juicy, and flavorful. Many customers like to wait right by the ovens so they can grab the freshest (and hottest) bird of the bunch. If that's you, you might have had days when you wonder: What's taking so long?

Chances are, your Costco warehouse doesn't always use the same supplier. These days, the chicken production process is owned and controlled entirely by Costco. But if the warehouse runs out of chickens from its regular supplier, it doesn't just stop selling them. Instead, employees say it replaces them with birds from a different supplier so that they can continue to stock the shelves.

A Costco employee explained this phenomenon on Reddit. "We mainly use Kirkland brand air cooled chickens in the deli, but sometimes we have to switch to water cooled chickens when we can't order enough ... which take longer to cook and tend to fall apart in the ovens more often. So some days it may take longer to get the chickens out since they're water chickens." Multiple other employees have backed this up over the years, with some even saying that's why the rotisserie chicken tastes different on occasion. The more you know.

If there's one thing Costco customers say is the most annoying thing about shopping at Costco, it's the receipt checkers. Admittedly, it's not fun to have to wait in a second line after finally making it through checkout, but those employees are there for a reason. Besides helping Costco save money by finding items that weren't scanned, they will also make sure you weren't accidentally overcharged.

Overcharging items at Costco happens more often than you might think, likely due to how often people are purchasing items in bulk — it's all too easy to accidentally scan the same item twice. Many Costco locations will also have shoppers keep their large items in the cart when going through the checkout line, which means a cashier may accidentally scan an item more than once. If they do catch an extra charge, the receipt checker will direct you to the returns counter to get an immediate refund.

Gold Star Costco members know that a part of the shopping experience is being asked if you'd like to upgrade to an Executive membership. The top tier comes with more perks — including 2% cash back on applicable purchases at the end of the year — but it's also more expensive. Many employees say they don't love having to question customers about upgrading their memberships, but behind the scenes, employees have said online that they actually have a quota to hit.

The exact quota and how strictly it's enforced can vary significantly by location. But it makes sense that employees are encouraged to help customers upgrade their memberships — after all, membership fees are how the warehouse giant keeps its prices low. According to Reddit posts from employees, they have daily, weekly, or monthly upgrade milestones to hit, which are generally assigned by store management.

If you are thinking about upgrading your Costco membership and want to help out your store's employees, consider waiting to upgrade in-person instead of doing so online. This will count towards an their quota. But again, there's no true guarantee that your local warehouse has set quotas for its workers.

Ever wondered why the number of cashiers at Costco's checkout line can vary so much? It's not just about how many are available. According to an employee on Reddit, Costco also checks the number of customers in the store in order to determine how many registers it should open.

Since every customer has to scan in to Costco, the store has a good understanding of how many shoppers are in the building at once. If the number peaks, Costco will have as many checkout lines open as possible. If the number is low, then cashiers can move to other positions throughout the store. Because Costco sees so many customers in one day, it cares about keeping its lines moving quickly so you never have to wait long — in 2026, it even implemented scan-and-go technology to speed up wait times. But for now, even if you only have a few lanes open at a time, that generally means the store is confident those lanes can handle the number of incoming shoppers.

On Reddit, some customers have said that they've had issues with getting the correct boxed appliances. According to both customers and employees, similar models of electronics can sometimes get mixed up as they get packaged in similar-looking brown cardboard boxes. This could result in you receiving a lower- or higher-quality product than what you actually paid for.

Employees recommend preventing this issue by simply opening the box in-store once you receive it from the electronics cage. Then, you'll be able to verify that the correct electronic is inside before you head home with it. If you do notice this issue upon returning home, you can simply head back to the store to exchange it for the correct product at the returns desk.

Generally, these types of switch-ups are very rare, so most customers don't know about this issue at all. Employees say that the electronic stocking and checking process is quite complex, with lots of guide rails in place so that mix-ups rarely happen. Even when something like this does occur, if the customer doesn't notice it themselves, chances are, store security will. Some customers have reported that they've been personally called by their local warehouse to return their purchase and swap it out for the correct model.

Everyone has had that moment at the grocery store where you reconsider one of the items in your cart. Because Costco is so large, employees say they regularly have issues with customers dumping items where they don't belong. They often have to throw out frozen or refrigerated products that get left on room-temperature shelves.

It's understandable that you might not want to navigate back to where you picked up a bag of chips or pack of bakery croissants, so instead of traversing the store to put it back, leave it in your cart until you get to the register. The cashiers at the checkout aisle will take the item for you and an employee will put it back where it belongs. Some even say that their Costco locations offer a designated spot at the checkout for you to leave items you're no longer interested in buying.

Costco is already good at loss prevention, given its robust security teams and receipt checkers, so it would be pretty difficult to waltz out of the store with something without paying. But while you're out filling up your cart, the regular people you bump into throughout each area of the store might not be shoppers at all. Costco hires plainclothes loss prevention workers to roam the aisles and report suspicious behavior.

Employees online have stated that they had no idea Costco even had a loss prevention team because they were so good at disguising themselves as customers (and that's kind of the idea). How loss prevention teams work can vary based on Costco location, but employee accounts online suggest that they most commonly work in high-value areas of the store, near places like electronics or alcohol (you never want to see someone sneaking out with a laptop or a bottle of champagne). But they're usually so good at their job that even your local warehouse's cashier might not know they're there!

We already know that employees might ask you to upgrade your Costco membership from Gold Star to Executive at random. The thought of being prompted to spend more money might be frustrating, but if you see a certain pop-up window appear while you're checking out, you might want to reconsider.

The price difference between the Gold Star and Executive membership is $65, making it double the price of what you would normally pay. Executive members get 2% cash back on all purchases at the end of the year up to $1,250, so the amount you'd need to spend at Costco to make the upgrade worth it is equal to $3,250.

Costco tracks your spending via your account history, so it knows how much money you've spent in the past year. If you make enough purchases to come close to the $3,250 number, employees say that the checkout screen will automatically prompt them to ask you if you'd like to upgrade your membership. While you might be tempted to dismiss the offer, you might want to consider taking that pop-up prompt the next time you see it because there's a chance you could actually save money by upgrading.

According to employees who have worked at Costco, the warehouses take food safety seriously. (That's something we love to hear, especially since many Costco locations offer fresh sushi and sashimi.) From the deli to the meat department, employees are trained to be very careful with how they handle themselves and the food.

In an interview with Mental Floss, one employee said that if someone "forgets to remove their apron before exiting the department, they must remove that apron, toss it into the hamper, and put on a fresh apron because now it's contaminated." Many employees have also stated online that they have to throw out any temperature-controlled food that has left their sight. Even if a customer returns it within a minute or two, it can't be reused.

Behind the counter, employees are very watchful of how customers handle the prepared foods and meats, and will quickly pull any items that have been put back by them. They'll quickly pull any items that have been put back by customers. They also keep an eye on fridge and warming station temperatures — and regarding those rotisserie chickens, they can only be out for two hours before being pulled and repurposed.

Ever wondered why your favorite brand of toothpaste is right up front next to the entrance one week, and in the back by the pharmacy the next? It's not just to make you explore the store for longer (though that's definitely an extra benefit for Costco). There are two terms that encompass the reason Costco's layout changes so frequently: 'mandatories' and 'hots.'

A 'mandatory' is the term for when a merchandiser pays Costco to feature their product in a prime location — such as the endcap of an aisle. Mandatory product placements change regularly; a merchandiser might pay Costco to display their items for just a week, or they could remain in a prime location for longer.

'Hots,' on the other hand, is the term for new products that don't necessarily have a designated spot in the warehouse. Employees will need to do their best to find a suitable location for these new products, which often means moving existing products around. So, both 'mandatories' and 'hots' can affect the layout of your Costco significantly and may cause things to change from week to week.