An angry customer is suing Anthropic on behalf of all users of its priciest subscription tiers.

In a federal lawsuit filed Monday, Karl Kahn accuses the Claude AI maker of misleading customers about the usage limits on its “Max 5x” and “Max 20x” plans and is seeking reimbursement, The Wall Street Journal reports, in a sign of the pushback Anthropic, and other AI labs, are receiving over the costs of their services, especially by power users.

Anthropic has emerged as the go-to provider of AI coding tools. Its cheapest coding plan, Claude Pro, costs $17 to $20 a month. But for heavy coding tasks, Anthropic offers Max 5x, which costs $100 a month, and Max 20x, which is an even more substantial $200 a month.

These offer much higher usage limits, but the lawsuit alleges customers aren’t getting what it says on the tin — namely, that Max 5x should give you five times the Pro cap, and 20x twenty times. This is what the language on Anthropic’s website still promises, but in reality it’s “far below the advertised amount,” the suit states, per the WSJ, claiming that the company’s marketing is fraudulent.

In Kahn’s experience, he found that he was hitting the weekly usage limit on his Max 20x subscription within weeks of upgrading to it, hitting 15 percent of his weekly usage in just one five-hour session.

He “found himself needing either to halt his work, ration his usage, or purchase additional usage to ensure that he could complete his work,” the suit alleges.

Coding is one of the most intensive tasks you can have an AI model do, and the culture around it prioritizes speed and volume. Vibe coders and software engineers will run multiple coding agents for hours at a time, racking up monthly bills in the thousands of dollars.

AI companies have become stricter about how much coding customers can do with their plans, transitioning to usage based billing that charges customers according to the number of tokens their tasks consume, which more closely aligns to the real-world computing costs that the AI provider incurs.

But as the latest lawsuit argues, these companies aren’t being transparent about how they’re tracking and calculating customer usage. The lawsuit has generated significant discussion in the r/ClaudeAI subreddit, with some echoing Kahn’s complaints — and others shouting it down because the 5x and 20x plans, in their eyes, provide incredible value.

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