The price on the shelf isn’t a suggestion. It’s a promise. And federal regulators say a chain you’ve probably shopped at has been breaking it for years.

On Oct. 26, the Federal Trade Commission and 20 states sued Dollar General, alleging the chain routinely rang up items for more than the price on the shelf tag, the sticker or the ad. The company runs more than 21,000 stores.

“Dollar General has betrayed the trust of millions of American consumers,” said Christopher Mufarrige, director of the FTC’s Bureau of Consumer Protection.

Those are allegations, not findings. Dollar General told CBS News it aims for shelf and register prices to match 100% of the time, that occasional mistakes happen at any retailer, and that “we will defend this litigation vigorously.”

But here’s what bothers me more than any one company. The national price-checking standard published for weights-and-measures inspectors lets a store miss on two out of every 100 items checked and still pass.

In other words, the system is built to tolerate some overcharges — and it leaves the noticing to you.

You can notice.

I’ve been writing about money for more than 35 years, and I’ve watched companies count on shoppers not paying attention the entire time. Here are six ways to catch a bad scan, get your money back and, in a few states, collect a little extra for your trouble.

1. Watch the screen, not your phone

The single best defense costs nothing: Look up while the cashier is scanning. Many registers show each item and its price as it rings up. That’s the moment an error is easiest to fix, because the item is still in front of you.

Once you’ve been scrolling through your phone for three minutes, the bags are packed and the line behind you is restless, checking the price on that jar of peanut butter feels like a hassle. That’s exactly the point where small overcharges become permanent.

This matters more than it sounds. When investigators for the New York attorney general went undercover at Dollar General stores, they were overcharged on 16 of the 114 items they bought. That’s 14%, or roughly one item in every seven.

At that rate, a 30-item shopping trip would include about four overcharged items. You won’t catch them if you aren’t looking.

2. Snap the shelf tag or sale sign

If you’re buying something because it’s on sale, take two seconds and photograph the tag or sign with your phone. Get the price and the product description in the frame.

Why bother? Because when you point out a mistake at the register, the first thing that often happens is someone gets sent back to check the shelf. Sometimes the tag has been taken down. Sometimes it’s for a slightly different size. A photo ends the argument before it starts.

It also gives you proof if you need to complain later, which I’ll get to in a minute. A dated photo of the shelf, next to a receipt showing a higher price, is about as clean as evidence gets.

You don’t need to do this for every can of soup, just the sale items and anything that seems like an unusually good price. Those are where the gap between the tag and the register tends to show up.

3. Check the receipt before you leave the parking lot

Missed it at the register? You’ve got a second chance, but only if you take it before you drive away. Sit in the car for a minute and read the receipt against what you remember paying.

Look hardest at sale items, multi-buy deals (2 for $5) and anything with a coupon. Those are the prices that require a store to update its system correctly, and that’s where things go wrong.

Here’s why the system lets this happen. Under the national inspection procedure in NIST Handbook 130, published with support from the federal government’s standards agency, inspectors at larger stores check 100 items. The store needs 98% accuracy to pass. A third error means it fails.

And the record suggests even that bar gets missed. The New York attorney general’s office reviewed 913 state inspection reports and found that 43% of Dollar General’s inspections from fiscal years 2021 through 2023 ended in price-accuracy failures.

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4. Point it out and ask for the posted price

Found an error? Go back in, politely, with the receipt and your photo. Don’t ask whether they can do something. Tell them the item rang up higher than the posted price and ask to pay the posted price.

Many stores will fix it on the spot. Dollar General itself says its store teams are supposed to fix it when a price is off. Hold them to that.

In New York, Dollar General no longer gets a choice. Under an agreement with the attorney general dated Oct. 13, its stores there must charge shoppers whichever price is lowest and post signs about that policy near every register.

If a clerk refuses, ask for a manager. If the manager refuses, get names, keep the receipt and the photo, and move on to step six. Don’t let a 75-cent dispute ruin your afternoon — let a regulator handle it.

5. Know your state’s payoff

Here’s the bonus from the headline. Getting the difference back is the baseline. Some states go further and reward you for catching the mistake. Four worth knowing:

Connecticut: The state’s “Get One Free” law says that if an item rings up above the shelf tag or the sticker on the item, you get it free, up to $20. It covers consumer commodities — things you use up and replace, like groceries, toiletries and paper goods.

The catch: You have to flag the mistake at the register and request the free item yourself.

Michigan: Under the state’s scanner law, you’re owed the difference. The store also has the option of paying a bonus of 10 times the difference, with a minimum of $1 and a maximum of $5.

To collect, tell the store within 30 days, face to face or in writing, and you’ll need the receipt.

Here’s the leverage: If the store fails to cover the refund and the bonus within two days of your notice, Michigan law lets you sue for $250 or your actual losses, whichever is more.

Say a $3.50 item rang up at $4.25. That’s 75 cents back, plus a $5 bonus if the store chooses to pay it, because 10 times 75 cents tops the cap.

Massachusetts: According to the state’s consumer guide to shopping rights, food stores that skip putting a price on every item (stores in the state’s waiver program) must hand you one of the items at no charge when it rings up above the lowest advertised price. At other food stores, you’re owed your money back on the spot.

Wisconsin: State regulators say a store that uses a scanner and overcharges you owes you a refund of the overcharge — whatever you paid above the posted or advertised price. No bonus, but the refund is the law, not a courtesy.

Everywhere else, the rules vary from state to state. To find out what you’re owed, check with your state attorney general’s office or your state’s weights-and-measures agency.

6. Report repeat offenders

If you keep getting overcharged at the same store, getting your 75 cents back isn’t enough. File a complaint. One shopper’s refund fixes one receipt. A pile of complaints is evidence. The FTC points to the complaints Dollar General itself received as proof the company knew about the problem.

Start with your state weights-and-measures office, the people who actually send inspectors into stores. In Michigan, for example, that’s the Department of Agriculture and Rural Development’s Weights & Measures section, at 800-632-3835. Your state attorney general’s consumer protection office is the other front door.

“Consumers deserve to trust the prices they see on store shelves,” Michigan Attorney General Dana Nessel said in a 2024 consumer alert on the state’s scanner law.

You can also tell the FTC at ReportFraud.ftc.gov.

Bring your evidence: the receipt, the photo of the shelf tag, the store address and the date. That’s what turns a gripe into a case.

The bottom line

A few cents here and there doesn’t sound like much.

But the FTC says Dollar General drew tens of thousands of consumer complaints, and the agency puts the alleged overcharges in the millions of dollars. Small amounts, multiplied across millions of shoppers, add up to real money — just not yours.

The fix takes about two minutes per trip: Watch the screen, snap the sale tags, read the receipt before you drive off, and speak up when you catch an error. In Connecticut, Michigan or Massachusetts, you might even come out ahead.

For the full story on the lawsuit, see “FTC, 20 States Sue Dollar General for Allegedly Overcharging Shoppers.” And for the other ways stores separate you from your money before you ever reach the register, read “Marketing or Manipulation? 30 Sneaky Ways Retailers Get You to Spend More.”