The U.S. Supreme Court declined on Monday to block a Texas law requiring app stores to verify user ages.
The App Store Accountability Act mandates parental consent for minors to download apps or make in-app purchases.
Justices denied an emergency request from students and tech groups to halt the law during ongoing litigation.
The Computer & Communications Industry Association, representing Apple and Google, argues the law violates the First Amendment.
Challengers claim the mandate unconstitutionally restricts access to protected speech and forces stores to police content.
A federal district court initially blocked the law before the 5th U.S. Circuit Court of Appeals allowed enforcement.
The Supreme Court's decision permits Texas to enforce the requirements while lower courts review the case.