US regulators filed a lawsuit on Monday accusing Uber of misleading users about promotional savings at Uber One subscription service and even signing them up without consent.

The Federal Trade Commission (FTC) argued in a legal complaint that the San Francisco-based company violated the Restore Online Shoppers' Confidence Act with tactics at Uber One.

"Americans are tired of getting signed up for unwanted subscriptions that seem impossible to cancel," FTC chair Andrew Ferguson said in a release announcing the suit.

"We're alleging that Uber not only deceived consumers about their subscriptions, but also made it unreasonably difficult for customers to cancel."

Uber One subscribers get discounts on rides or food deliveries made using an Uber Eats service.

Subscriptions typically cost about US$10 monthly. Uber enticed people to sign up with a promise of US$25 monthly in savings, but that did not apply to subscription fees, according to the complaint.

FTC attorneys argued that Uber's promise of monthly savings was misleading, and that the company made it difficult for users to terminate Uber One subscriptions despite saying they could easily "cancel anytime."

Uber denied signing people up without consent and said most cancellations of subscriptions take less than 20 seconds in the app.

"We are disappointed that the FTC chose to move forward with this action," an Uber spokesperson told AFP.

The spokesperson added that Uber was "confident that the courts will agree with what we already know: Uber One's sign-up and cancellation processes are clear, simple, and follow the letter and spirit of the law." (AFP)