14 Unspoken Costco Rules Members Need to Know

I’ve been a Costco member for 18 years, and I’ve learned that shopping at Costco comes with a few unwritten rules. Some you pick up quickly, while others are easy to miss, even after years of membership.

From sample etiquette to checkout routines and spotting clearance prices, here are 14 unspoken Costco rules worth knowing before your next trip.

1. Have Your Membership Card Ready Before You Reach the Entrance

The entrance is one of the easiest places to create a bottleneck. You’re pushing a cart, people are coming up behind you, and suddenly you’re searching through your purse for your membership card.

Get your card out, or open your digital membership card in the Costco app, before you reach the door. Costco requires members to scan their membership card when entering and present it again at checkout.

The unspoken part is being ready so everyone behind you can keep moving.

2. Know the Self-Checkout Etiquette

One of my Costco pet peeves is when shoppers form a separate line for each row of self-checkout kiosks. There is only one line at the self-checkout, join it and wait for the next available kiosk. Don’t start your own line.

Scan smaller items and place them in the designated area next to the scanner. Leave large, bulky items in your cart and ask a staff member to scan them with a handheld scanner.

3. Practice Good Cart Etiquette

Costco carts are big, and a cart parked sideways can make even a wide aisle difficult to navigate. If you want to browse a display, compare prices, check your phone, or catch up with someone you know, pull your cart aside first.

Avoid leaving it in the middle of an aisle while you walk away to grab something. Your cart might be blocking the very shelf someone else needs.

If you’re shopping with family, leave room for other shoppers to pass rather than spreading your group across the aisle. A little awareness goes a long way on a busy Costco afternoon.

4. Know the Checkout Etiquette

Checking out at Costco feels a little different from a regular supermarket, especially when it comes to unloading your cart and knowing where to stand.

First, have your membership card ready. The cashier needs to scan it before ringing up your purchases, so getting it out ahead of time helps keep the line moving.

Unload smaller items onto the conveyor belt, but leave bulky or heavy items in the cart for the cashier to scan with a handheld scanner. There’s no need to lift a heavy case of water onto the belt. Follow any additional instructions from the cashier or checkout assistant.

Know that there is a separate cart lane, send your cart down the cashier’s side while you walk down the customer side to pay. This gives the checkout team room to scan the items left in your cart and load your purchases back in.

5. Bring the Right Credit Card

If you’re paying by credit card at a U.S. Costco warehouse, bring a Visa. Costco does not accept other credit cards, such as Mastercard, American Express, or Discover.

You don’t need Costco’s own credit card. A regular Visa credit card works, and other payment options include cash, most PIN-based debit cards, and Costco Shop Cards.

If you’re visiting a Costco in Canada, the usual credit card rule is different: Canadian warehouses accept Mastercard rather than regular Visa credit cards.

6. Your Membership Card Isn’t Something You Can Lend Out

If someone asks to borrow your card for a quick Costco run, know that membership cards are nontransferable.

Costco allows members to bring children and up to two guests, but says only members may purchase items.

If a friend wants to see what Costco is like, bring them along as your guest rather than handing over your card. Set that expectation before you get to checkout.

7. Know the Sample Etiquette

Free samples are part of the fun of shopping at Costco, but a little patience makes the experience better for everyone.

Wait until the samples are ready and set out before taking one. Don’t reach across the station or grab food from the prep area. Take one at a time, especially when there’s a line, and let other shoppers have a turn before going back for more.

Once you have your sample, move away from the tray to eat. If you want to discuss whether it’s worth buying, pull your cart aside so you aren’t blocking the station or the aisle.

Don’t send children up to collect samples on their own. Go with them so the person serving can get a parent’s or guardian’s approval.

Children can be refused a sample without an adult present because of food allergy concerns. Being nearby also gives you a chance to check the ingredients before your child tries anything.

You don’t have to buy it just because you sampled it. Say thank you, and put your empty cup or toothpick in a trash can rather than leaving it on a shelf.

8. Keep Your Receipt Handy Until You’re Outside

After paying, keep your receipt out. Don’t tuck your receipt into the bottom of a bag and don’t throw it away.

Costco inspects receipts and merchandise as members leave. It’s a standard part of the shopping trip.

Keep yours somewhere easy to reach, particularly if you stop at the food court before heading out.

The unspoken rule is having your receipt ready when it’s your turn to leave, so you don’t have to search for it while the line waits behind you.

9. Make Room for Other People at the Food Court

Between carts and people waiting for orders, the food court can get crowded quickly.

Keep your cart out of walkways and avoid blocking the pickup area while you wait. Listen for your order and step forward when it’s ready.

If you sit down to eat, clear your trash when you’re finished. When seating is tight, avoid using an extra table just to hold your shopping bags.

A little awareness makes it easier for everyone to enjoy their meal.

10. Prices Ending in .97 Are a Clearance Clue

Costco does not use big clearance signs. Instead, look at the last two digits of the price.

A price ending in .97 generally signals a clearance markdown. If you spot something for $9.97 or $14.97, it’s worth taking a closer look, especially if it’s something you already planned to buy.

Prices and markdown timing can vary by warehouse, so a deal someone shares online might not be available at your location. And .97 doesn’t guarantee the lowest possible price. An item could be marked down further, but waiting also means risking it selling out.

11. The Asterisk Is a Clue That an Item May Not Be Restocked

See an asterisk in the corner of a Costco price sign? Shoppers often call it the “death star” or “star of death.”

It generally signals that the warehouse isn’t planning to reorder that item. That doesn’t necessarily mean it’s gone forever. It could be seasonal or return in a different version later.

The asterisk also doesn’t automatically mean the item is on sale. Check the price separately.

If it’s a favorite your family uses regularly, I suggest stocking up because you don’t know if or when it’s coming back.

12. Don’t Leave Cold Food on a Random Shelf

You might put a refrigerated meal in your cart and then find something else you’d rather have for dinner. That happens.

But a package of chicken or a tub of yogurt doesn’t belong beside the paper towels while you finish shopping.

Return it promptly to its proper refrigerated or frozen section. If you can’t, tell an employee or hand it to the cashier and explain that you changed your mind.

If it has been sitting out, let them know. Don’t assume putting it back in a cooler makes it suitable for the next shopper.

13. Leave Sealed Packages Sealed

When you’re buying in bulk, it’s understandable to want a closer look at what’s inside. But opening a sealed food package or breaking apart a multipack can leave an item that another member won’t want to purchase.

Use the display item when one is available. If you need help checking a product, ask an employee.

The same courtesy applies to clothing tables. You can check a size without leaving several unfolded stacks behind.

14. Return Your Cart to a Cart Corral

Once you’ve loaded your car, you’re almost done.

Return the cart to a designated corral rather than leaving it in an empty parking space or wedging it onto a curb.

Come shopping with me on YouTube

Here’s my latest Costco haul, including what I bought, what I’d buy again and the new items I spotted. Subscribe to the Suburbs 101 YouTube channel.