In California, retailers generally do have to honor price mistakes when the mistake is a posted or advertised price in a store. Under the state’s Price Accuracy Law, commonly called the Scanner Law, a store must charge the lowest price it has posted, advertised, marked, displayed, or quoted for an item. If a shelf tag says $29.99 and the register rings $49.99, the $29.99 price controls. The rule has real limits, though. Online glitches, a handful of exempt product categories, and decimal-point errors severe enough to shock a court all sit outside its reach.
The Rule: California’s Scanner Law
The core protection is Business and Professions Code Section 12024.2. It makes it unlawful to charge more than the lowest price posted, advertised, marked, displayed, or quoted for an item, and when more than one price appears for the same product, the store owes you the lowest one.1California Legislative Information. California Business and Professions Code 12024.2
The statute looks at the price the store presented to you, not at what the store meant to charge. An old sale tag left up after the promotion ended is still a posted price. A shelf sign that no longer matches the register is still a posted price. Intent does not rescue the retailer from the obligation to honor what shoppers can see.
Conditions Have to Be Posted With the Price
A retailer can attach conditions to a price, like requiring a loyalty card, a minimum quantity, or a multi-item purchase. But the condition has to be conspicuously posted in the same location as the price itself.1California Legislative Information. California Business and Professions Code 12024.2 A footnote in tiny print, or a disclaimer posted somewhere else in the store, does not do the job. If the condition is not visible next to the price, the price stands on its own.
Where the Law Does Not Reach
California’s item-pricing rules for grocery stores using point-of-sale scanners carve out several categories from the requirement that individual items carry price labels:
- Unpackaged fresh produce.
- Very small items under three cubic inches, weighing less than three ounces, and priced under $0.40.
- Sale and special items offered at a promotional price.
- Items sold through vending machines.
- Small family-run businesses whose only regular employees are the owner, immediate family, and no more than two others.
These exemptions come from California Civil Code Section 7100 and address whether each item needs an individual sticker. They do not undo the broader Scanner Law rule. A store can skip stickering loose apples, but if it posts a shelf sign saying apples cost $1.99 per pound, it cannot ring them at $2.49. Sale items are the same story: the store does not have to price-tag each one individually, but the posted sale price has to be honored at the register.
Online Pricing Mistakes Work Differently
The Scanner Law targets prices “posted” or “displayed,” which courts have generally read to mean physical shelf tags and in-store signage rather than website listings. For online purchases, the question is whether a contract ever formed at all.
Most online retailers write their terms of service so that clicking “place order” does not close the deal. A contract typically forms only when the company ships the product and sends a shipping confirmation. Until then, the retailer reserves the right to cancel, including orders placed at a mistaken price. If a $2,000 television gets listed at $200 because of a database error, the retailer can void the order and refund the charge without ever shipping.
When that happens, federal rules govern the refund timing. Under the FTC’s Mail, Internet, or Telephone Order Rule, a seller must issue a refund within seven working days of the date the buyer’s right to it arises. If the payment was made on a credit account where the seller is the creditor, the timeline extends to one billing cycle.2eCFR. Mail, Internet, or Telephone Order Merchandise
The practical takeaway: an online “deal” that looks too good is not yours until it ships.
Extreme Errors and the Unilateral Mistake Defense
Even for an in-store purchase, a retailer facing a genuinely severe pricing error has a potential escape under general contract law. Courts can rescind a contract based on a unilateral mistake when the error concerns something fundamental to the deal and enforcing the contract would be unconscionable. The retailer also has to show it acted with ordinary diligence and that the buyer can be restored to their original position, usually through a refund.
This defense is narrow. A shelf tag reading $29.99 instead of $34.99 will not qualify; the gap is too small to be unconscionable. A decimal-point error pricing a $5,000 appliance at $50 is the kind of scenario a court might rescind. The defense also tends to fail when the retailer’s own carelessness produced the error, because the ordinary-diligence requirement cuts against sloppy pricing. In everyday disputes, the Scanner Law resolves the question long before this doctrine matters.
When the Mistake Is Not a Mistake
If a retailer routinely advertises a low price and then tells shoppers at the register that the “real” price is higher, that pattern moves from carelessness into false advertising territory. Business and Professions Code Section 17500 makes it unlawful to disseminate advertising that is untrue or misleading when the advertiser knew, or should have known with reasonable care, that it was.3California Legislative Information. California Business and Professions Code 17500 The statute specifically reaches anyone who advertises property at a price they never intend to honor. Federal rules reinforce this: the FTC’s Guides Against Bait Advertising require a retailer to have enough stock at all listed locations to meet reasonably anticipated demand for an advertised item unless the ad clearly discloses that supply is limited.4eCFR. Guides Against Bait Advertising
What the Retailer Risks
The Scanner Law carries criminal penalties that scale with the size of the overcharge:
- For overcharges above $1, a willful or grossly negligent violation is a misdemeanor. The fine runs from $25 to $1,000, with up to one year in county jail, or both.1California Legislative Information. California Business and Professions Code 12024.2
- For overcharges of $1 or less, the violation is an infraction with a maximum fine of $100.1California Legislative Information. California Business and Professions Code 12024.2
These penalties target the retailer, not the cashier. County weights and measures offices are the primary enforcement agencies, and repeat offenders draw closer scrutiny.
What to Do at the Register
Photograph the shelf tag or sign before you leave the aisle. Timestamped phone photos make strong evidence if the tag disappears later. At checkout, point out the discrepancy calmly and ask the cashier to adjust the price. If they cannot fix it, ask for a manager. You do not need to cite statute numbers; saying “Under California’s Scanner Law, the store has to charge the lowest posted price” communicates that you know the rule.
Most managers will correct the price on the spot. The cost of a single adjustment is trivial next to the risk of a regulatory complaint. If the store refuses, do not argue. Buy the item at the higher price if you still want it, keep the receipt, and file a complaint with your county’s weights and measures office. These offices are the designated enforcement agencies for pricing accuracy in California.5NIST. Price Verification FAQs Most accept complaints online or by phone. Include the store name and address, the product, the posted price, and the price you were charged.
For a pattern of overcharges or a retailer that flatly refuses to comply, the Consumer Legal Remedies Act under Civil Code Section 1770 provides additional options. It lists specific deceptive practices and allows harmed consumers to seek damages beyond the price difference. Small claims court is available for individual disputes, though the filing fees and time involved usually make sense only when the overcharge is significant or the principle matters to you.