Costco is facing a major class-action lawsuit over its Kirkland Signature tequila line. The lawsuit claims the retailer marketed its tequila as “100% agave,” but testing suggests that may not be entirely true. This case highlights the importance of accurate marketing and labeling in the beverage industry and serves as a warning for brands that premium claims come with serious responsibilities.

What the Lawsuit Alleges

Filed in November 2025, the lawsuit targets Costco’s Kirkland tequilas, including Blanco, Reposado, Añejo, Añejo Cristalino, and Extra Añejo. Plaintiffs claim that despite the labels claiming “100% de Agave” or “100% Agave Azul,” some of the products contain ethanol from non-agave sources. Customers who paid premium prices may have been misled about the quality and authenticity of the tequila.

The legal complaint highlights several key points:

• Costco’s labeling may constitute deceptive marketing and unfair business practices

• Consumers were allegedly led to believe they were purchasing only pure agave tequila

• Testing methods such as Nuclear Magnetic Resonance (NMR) and isotope analysis suggest the presence of non-agave sugars

• Questions were raised about the oversight of the Consejo Regulador del Tequila, the regulatory body for tequila production in Mexico

Legal and Regulatory Implications

The lawsuit cites potential violations of both state and federal laws, including consumer protection statutes. The case also references the Racketeer Influenced and Corrupt Organizations (RICO) Act, suggesting a possible broader pattern of misconduct. The outcome could have implications not only for Costco but for other brands that make similar premium claims without proper verification.

What This Means for Consumers

Consumers should be aware that marketing claims, especially for premium products, can carry legal weight. Misleading or inaccurate claims may affect:

• Price expectations and perceived value

• Confidence in product authenticity

• Access to remedies such as compensation or corrective labeling if claims are proven false

This case serves as a reminder that consumers rely on labels and marketing to make informed purchasing decisions.

Lessons for Marketers

For brands and marketers, the lawsuit is a cautionary tale:

• Ensure all claims are verifiable and backed by reliable evidence

• Understand that premium labels carry higher expectations and scrutiny

• Regulatory compliance is not optional; failing to meet standards can result in costly lawsuits

• Keep internal documentation of product testing and approvals to defend marketing claims if challenged

By integrating compliance into marketing workflows, brands can maintain customer trust while avoiding legal pitfalls.

Costco’s Kirkland Signature tequila lawsuit demonstrates how even small marketing claims can have significant consequences. Accuracy, transparency, and compliance are essential for maintaining brand integrity and consumer trust. For marketers, this is a reminder that behind every product label lies both opportunity and responsibility.