Starbucks is being accused of failing to fill lattes to the brim

Starbucks is being sued for allegedly failing to fill its coffee cups to the brim.

A class action lawsuit claims the coffee chain has been underfilling its lattes by roughly 25%, Buzzfeed News reports.

"Starbucks lattes are made from a standardized recipe, which Starbucks instituted in 2009 to save on the cost of milk - one of its most expensive ingredients," the complaint reads.

The suit argues that the "fill-to" lines on the pitchers that baristas use to heat milk are mismarked, resulting in drinks that fall short of 12-ounce tall cups, the 16-ounce grande cups, and the 20-ounce venti cups.

"By underfilling its lattes, thereby shortchanging its customers, Starbucks has saved countless millions of dollars in the cost of goods sold and was unjustly enriched by taking payment for more product than it delivers," the suit reads.

California residents Siera Strumlauf and Benjamin Robles filed the lawsuit on behalf of all purchasers of Starbucks lattes. The suit accuses Starbucks of violating California's consumer laws and of "negligent misrepresentation and fraud."

Starbucks said it's aware of the lawsuit.

"We are aware of the plaintiffs' claims, which we fully believe to be without merit," the company said in a statement. "We are proud to serve our customers high-quality, handcrafted and customized beverages, and we inform customers of the likelihood of variations."

Subway was recently sued for a similar complaint.

The lawsuit claimed that the chain's footlong sandwiches are shorter than advertised. Subway has since agreed to start requiring franchisees to measure the bread they serve to ensure that footlong subs are 12 inches and 6-inch subs are no less than 6 inches.

A judge also ordered Subway to pay $520,000 in attorney fees and $500 to each of the 10 people who were representatives of the class.