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When you like something, it's natural to want to share it with others. However, if that "something" is your Costco membership card, you should definitely think twice before sharing.

Costco membership is non-transferrable. This means only you can use your membership card. Each membership comes with two cards, so you can add one member of your household. Otherwise, you're allowed up to two guests while you shop -- but a member must pay at checkout.

Some folks may try to skirt this policy by lending a friend or family member (or, worse, a stranger) their membership card. Unfortunately, this is a risky choice that is likely to backfire.

They'll probably get stopped at checkout

As most regular Costco shoppers already know, you need to show your membership card often. Often, you need it just to get through the door (other than guests).

More importantly, you definitely need it to check out. Even if you use self-checkout, you're going to have to scan a membership card. Plus, an employee may also check your card -- and the picture of you on it -- before you even start checking out.

If the person doesn't match the picture on the card, they won't be able to check out. You may also be subject to some questions about how they came to be in possession of your card.

Misbehavior will come back on you

Should the stars align and someone gets through checkout using your membership card, you're not necessarily off the hook. That purchase is now forever tied to your membership account. If anything hinky occurs, it's easily traced back to you.

For example, say you scan your membership card for a stranger and it turns out they used a stolen credit card. Guess whose name and address is on file for that transaction? Hint: It's not them.

While it's unlikely you'd wind up in legal trouble if you can show you weren't the perpetrator, you'll still need to admit that you broke the terms and conditions of your membership. Which leads to…

Your Costco membership could be revoked

If there's an honest mistake -- perhaps you didn't realize your teenager couldn't check out with your membership card -- then you'll likely get a warning. Folks with a history of misuse, however, will typically have their membership revoked.

Fun fact: Costco (and pretty much any other business or organization) can revoke your membership at any time, for any reason (not prohibited by law).

Sharing your membership card is specifically against the rules of said membership. Costco is well within its rights to revoke that membership if you break the rules. And the company will happily do so. Costco has 130 million cardholders -- it isn't worried about losing one or two.

Gift them a Costco Cash Card instead

If you really want to share the Costco experience, there are a few ways your friends and/or family can check out Costco with you:

• You can bring them as a guest. You get up to two guests per visit. Keep in mind that only members can make purchases, so you'll need to put anything they want to buy on your own credit card and have them pay you back later. (On the plus side, more credit card rewards for you!)
• You can add them as your second cardholder. If you're the Primary Member, you can add someone else from your household to your account. They'll get their own card and have all the same shopping privileges you do.
• Gift them a Costco Shop Card. Only members can buy Costco Shop Cards, but non-members can use them to pay for Costco purchases. Note that Costco's usually generous return policy may not apply to returns made by non-members.

It's always fun to share what we love with the people we love. But there's a right way to do it -- and a wrong way. Make sure you're choosing the right way to share your Costco love so you don't wind up on the wrong side of the rules.

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