Walmart (NYSE:WMT), the world’s largest retailer, is set to face a lawsuit alleging it frequently charges higher prices at the register than those displayed on store shelves, potentially costing consumers hundreds of millions of dollars annually.

This decision comes after the 7th U.S. Circuit Court of Appeals in Chicago reversed a lower court ruling on Wednesday, allowing the proposed class action to proceed.

The appellate court's decision, written by Circuit Judge David Hamilton, stated that consumers could reasonably attempt to prove that Walmart's practices constituted a fraudulent "bait-and-switch" scheme, which violates multiple state consumer protection laws.

The court dismissed Walmart's defense that providing receipts after purchases mitigated any unfairness caused by shelf price inaccuracies.

Judge Hamilton emphasized that it was "neither unreasonable nor fanciful" for consumers to expect Walmart to charge the prices displayed on shelves.

The lawsuit claims that price discrepancies were found in several states, including Florida, Illinois, Indiana, Maryland, New Jersey, New York, and North Carolina. 

Examples of these discrepancies include a Walmart store in New Jersey charging $3.64 for Crisco Pure Canola Oil compared to the $3.12 shelf price, and another store charging $2.48 for Hershey's Chocolate Syrup versus the $2.33 shelf price.

While individual discrepancies were small, the plaintiffs argue that these differences accumulate significantly over time, impacting consumers nationwide.