A US federal judge found Amazon liable for unfairly billing parents for in-app purchases made by children, following a case filed by the Federal Trade Commission (FTC).

FTC Chairwoman Edith Ramirez said: “We look forward to making a case for full refunds to consumers as a result of Amazon’s actions.”

The judge’s order calls for further details from the watchdog and Amazon regarding how much the latter owes consumers.

The FTC’s case against Amazon was first filed in July 2014. Back then, it wanted Amazon to change the process by which purchases can be made in the app store, “permanently banning the company from billing parents and other account holders for in-app charges without their consent”.

The FTC said freemium apps aimed at children, which are free to download but support in-app purchases of digital items via an associated credit card, can be problematic. Tap Zoo and Ice Age Village were cited by the FTC as games in which this has commonly taken place.

The FTC said disclosures about the possibility of these charges within “freemium” apps were not enough.

In the past, the FTC has reached settlements with Apple and Google related to such charges, requiring the companies to fully refund consumers, resulting in refunds of more $50 million.

Back in February last year, Apple, Amazon, Google and Gameloft agreed to remove the word ‘free’ from ‘freemium’ apps in Italy, following an investigation by the Italian competition authority in cooperation with the European Commission.