3 Wild Costco Rules You May Not Realize Exist

Certain rules pertain to Costco that most members are aware of. For example, you have to show your membership card at the door, and you need to have your receipt looked at by a store employee before heading out.

But some Costco rules may be less obvious -- and really surprising. Here are three wild rules you'd think wouldn't be correct -- but they are.

1. You can bring back partially eaten food

Costco is known for its generous return policy. Bought a jacket that sat unused in your closet for seven months? Costco will take it back. But did you know that Costco will take back food products -- including those that have already had a bite taken out?

It's true. Costco will take back partially eaten food on the condition that you're returning at least 50% of it. So if you buy a cake and you find that it doesn't taste the way you expected it to, you can return it even with a few slices missing.

2. You're guaranteed not to lose out financially with an Executive membership

An Executive membership at Costco costs twice as much as a basic one -- $120 a year versus $60. In exchange for the higher price point, the Executive membership gives you 2% cash back on your Costco purchases.

You need to spend more than $3,000 a year on your credit card at Costco for the Executive membership to pay off. That's because 2% of $3,000 is $60 -- the cost of your upgrade. Once you've spent more than that (even $1 more), you win.

However, you don't have to worry about not making your money back with an Executive membership. If you don't earn enough cash back to reach the $60 mark, Costco will let you downgrade to a basic membership after a year. At that point, you'll be refunded the difference between $60 and the amount of cash back you did rack up. So if you only spend enough to get $40 back, at the time of your downgrade, Costco will refund you $20.

3. You can shop at Costco for 364 days for free

Costco guarantees complete customer satisfaction on everything it sells -- including its memberships. If you're unhappy with yours, you can cancel at any time for a refund. What this technically means is that you're able to shop at Costco for 364 days for free. As long as you cancel ahead of the one-year mark, you can get your fee back.

However, don't try pulling this trick repeatedly -- Costco will catch on. To put it another way, your free 364-day shopping pass is probably a one-time deal.

Remember, too, that Costco uses the money it collects from membership fees to offset its costs and offer its super low prices. So if you cancel after 364 days to game the system, you're hurting consumers everywhere.

The more you know about Costco, the more value you might get from your membership. It pays to read up on the details to get the best bang for your buck at Costco. And if you have questions about any of the store's rules, don't hesitate to visit customer service and ask away.