The Costco Rule You Must Follow When Bringing Your Own Shopping Bags

Our favorite warehouse retailer, Costco, doesn't provide shopping bags for a few reasons: plastic bags are wasteful, they cost the company money that could otherwise be passed along in customer savings (why do you think the Costco hot dogs remain so cheap?), and a lot of the stores' jumbo-sized products wouldn't fit in a typical shopping bag, anyway. If you don't want to grab one of the boxes by the exit and condense your groceries in the trunk of your car like a ton of Costco-ites do, you are free to bring your own reusable shopping bags ... as long as you are okay with them being checked. This may happen both at the entrance to make sure that they are empty and again at the exit to make sure the items inside match up with what's on your receipt.

Costco's online rundown of membership privileges and conditions states that the retailer "reserves the right to inspect any container, backpack, briefcase, or other bag, upon entering or leaving the warehouse," and reinforces what you already know ... employees can and will check your receipt and shopping haul before you leave. You probably won't find a fabric tote big enough to fit the legendary Costco barrel of Jack Daniel's — or, more realistically, a bulk pack of TP or Kirkland Signature chicken stock — but, whatever you do manage to stash in your personal bags will be checked, because minimizing theft is one of the many ways that Costco keeps prices low.

Have you ever wondered why Costco has one way in and one way out? The choice, like so many others that you may not even notice at Costco, is meant to deter shoplifters. It's the same reason why Costco has cracked down on showing IDs and membership cards at checkout — although, in some states, you can buy alcohol at Costco without a membership — and why some of its packages, even for small items like razor blades, are so unwieldy. It's not that easy to conceal a 10-pound chub of ground beef under your clothes the same way that an unscrupulous person might try with a small one, after all. 

Costco's legacy was built on its low prices and the great way it treats its employees. For the company to keep maintaining those advantages, it needs to hone in on the operating costs it can control. Costco has focused on what retailers call "shrink," specifically the kinds that come from employee or customer theft. And it is doing a great job: the company enjoys a lot less theft than competitors, even in the face of risky advances like self-checkout.

The next time you get frustrated by the excessive attention that the Costco door employee is giving your personal shopping bags, take a deep breath. The delay might be a little annoying, but it's indirectly helping you enjoy discounts on the shelves as increasing retail inflation makes costs spike almost everywhere else.