Ever wonder what staff members are checking when you leave this store? Here's the logic behind this step

You've loaded up your trolley with enough toilet paper to last you for a while, navigated the warehouse maze, and survived the checkout queue.

Yet, there's one final hurdle between you and travelling back home: that friendly Costco employee with the highlighter pen, ready to scrutinise your receipt.

If you're like most shoppers, you probably assume this ritual is all about catching sneaky customers. After all, why else would they bother checking? The reality, however, might surprise you.

It's about protecting your wallet, not theirs

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Costco's receipt checking policy isn't designed to catch shoplifters.

According to Kevin Heuer, the general manager of Costco's San Francisco store, 'We want to make sure they're not getting overcharged and they're not getting undercharged. It's not to target shoplifters.'

The policy, which has been standard practice since the first Costco store opened in 1983, serves a purpose entirely different from what most people imagine.

'It's our most effective method of maintaining accuracy in inventory control, and it's also a good way to ensure that our members have been charged properly for their purchases,' the company explained on its website.

'If there's an extra item in their basket, that's not their fault. That's our fault. Sometimes, checkers forget to ring up items placed on the bottom of the basket,' Heuer added.

What are they actually checking?

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The staff aren't just randomly glancing at your receipt and trolley.

According to Costco employees who spoke to Business Insider, they're looking for several specific things.

The daily code system is written as a letter followed by a number. It changes every day to indicate when the receipt was printed.

This confirms your purchase and receipt were made on the same day.

Real money-saving success stories

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This isn't just theory—there are genuine examples of customers being saved from costly mistakes.

One shopper shared how a receipt checker identified a discrepancy where they'd been charged for three items instead of two.

The overcharge, which exceeded $75, was promptly rectified with a refund.

In another case, a checker noticed an error between the number of items in the trolley and the items listed on the receipt.

The checker discovered an unscanned case of La Croix at the bottom of the trolley that the cashier had missed.

However, it doesn't always work in the customer's favour. Another customer shared how a receipt check revealed a cashier had missed scanning several items.

How does this compare to other retailers?

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Costco's approach is working remarkably well compared to other major retailers.

While other big-box retailers are reporting significant losses due to theft, Costco's CFO Richard Galanti noted in an earnings call, 'We haven't seen any major change in shrinkage. We've been fortunate in that regard.'

This success may seem counter-intuitive, given the apparent 'security gap' identified in the original Australian experience, where staff only count items rather than verifying actual contents.

However, the membership model itself poses a significant deterrent. Every purchase is linked to your membership, letting store employees easily access your past orders and identify any irregularities.

The psychology behind the assumption

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The receipt checking process can feel uncomfortable for innocent shoppers.

This psychological reaction is natural, but as one noted, 'like that cop who just happened to turn in behind you, there's nothing really sinister about it.'

When signing up for a Costco membership, shoppers also agree to allow receipt checking as part of the membership agreement.

Making the most of the process

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Understanding what's really happening can help you navigate the exit more smoothly.

Check your own receipt as you approach the exit, looking for any obvious mistakes, such as incorrect item quantities or items that may have been split incorrectly.

If something seems off, it's better to contact customer service to clarify the issue before attempting to leave.

So, the next time you're waiting in that familiar exit queue, remember that the person with the highlighter isn't there to catch you doing something wrong—they're there to make sure Costco hasn't done something wrong to you.

In a world where retail theft is on the rise and customer service can feel impersonal, it's refreshing to know that a major retailer has built its entire exit strategy around protecting customers' wallets.

What's been your experience with Costco's receipt checking? Have you ever had them catch an error that saved or cost you money? Share your stories in the comments below.