Costco shoppers are used to walking in for paper towels and walking out $280 lighter.
But a quiet policy shift rolling out across warehouses is making some of those impulse buys harder to pull off, and it could change the way you plan your trips.
The company has been tightening enforcement around membership sharing, adding card scanners at entrances and requiring photo verification at self-checkout.
Costco says the moves protect paying members, since membership fees make up a huge chunk of its profit and help keep shelf prices low.
For the average household, the math is simple: if you're splitting a $65 Gold Star membership with a neighbor or using your mom's card, that workaround is getting riskier.
Employees are now trained to stop transactions when the person at the register doesn't match the photo on the account.
That matters because Costco's deals are genuinely competitive.
Rotating instant savings booklets knock $3 to $8 off everyday staples like coffee, laundry detergent, and snack bars, often stacking with manufacturer coupons.
The catch is that these discounts rotate every few weeks, so timing a stock-up run can save $40 or more on a single cart.
Costco fuel routinely runs 20 to 40 cents below nearby stations, and the gap widens during holiday travel weekends.
If you fill a 15-gallon tank twice a month, that's roughly $10 to $15 in monthly savings, which can cover a chunk of the annual membership on its own.
The pharmacy and optical departments don't require a membership at all, a rule many shoppers don't know.
Prescription prices are often lower than chain drugstores, and the hearing aid and eyeglass centers post transparent pricing.
You can also order online for delivery without joining, though a 5% surcharge applies to non-members.
Kirkland Signature remains the sleeper deal.
The store-brand products are frequently made by the same manufacturers behind name brands, and Consumer Reports has ranked several of them ahead of the national labels in taste tests.
Swapping just five regular items to Kirkland can trim a grocery bill noticeably over a year.
One warning worth repeating: the famous $1.50 hot dog and soda combo is a loss leader, not a savings strategy.
Neither is upgrading to Executive membership for the 2% reward unless you're already spending around $3,250 a year, the rough break-even point after the higher fee.
The practical takeaway is to treat Costco like a tool, not a hobby.
Go in with a list, check the current instant savings flyer before you leave the house, and skip the aisle wandering that turns a $60 trip into a $200 one.
My take: Costco's crackdown stings for households that leaned on shared cards, but it's hard to argue with a model that keeps prices down for the people actually paying.
Final Thoughts
If you're already a member, the real savings come from discipline, not from the membership itself.