The US Federal Trade Commission FTC, has sued Amazon, alleging it allowed millions of dollars of unauthorised purchases by children in its mobile app store.
The FTC is seeking refunds for parents who were charged.
Amazon resisted a settlement offer from the FTC, and wrote in a letter to the regulator earlier this month, that it would not accept tighter controls.
In January, Apple settled with the FTC over similar charges.
FTC chair Edith Ramirez said Amazon’s in-app system allowed children to incur unlimited charges on their parents’ accounts without permission.
In response to the allegations, an Amazon spokesperson cited a letter the firm sent to the FTC on 1 July in which it wrote it was “deeply disappointed” by the FTC’s demand.