T-Mobile and Sprint have exhausted their latest effort to overturn nearly $92 million in federal penalties after the US Court of Appeals for the District of Columbia Circuit declined to reconsider an earlier ruling that upheld fines imposed by the Federal Communications Commission.

In a brief order issued Friday, the full DC Circuit rejected the wireless carriers’ consolidated request for an en banc rehearing, leaving in place a prior panel decision that affirmed the FCC’s forfeiture orders. No judge requested a vote on whether the court should revisit the case, effectively closing the door on further review at the appellate level.

The penalties stem from a long-running FCC investigation into how major wireless providers handled sensitive customer location data. Regulators concluded that T-Mobile and Sprint allowed third-party data aggregators to access and resell consumers’ real-time location information without obtaining proper authorization, in violation of federal customer privacy rules.

Following the investigation, the FCC imposed an $80 million fine on T-Mobile and a separate $12 million penalty on Sprint. The agency determined that the companies failed to adequately safeguard customer proprietary network information, a category of data that includes precise location details and is subject to strict federal protections.

The carriers challenged the enforcement action, arguing that the FCC had exceeded its authority and misapplied the law. A three-judge panel of the DC Circuit rejected those claims earlier, prompting the companies to seek rehearing before the full court.

With the denial of that request, the appellate court has now left the FCC’s enforcement decision intact. The ruling brings an effective end to the carriers’ attempts to revive their appeal within the DC Circuit, barring further action at the Supreme Court.

The case is part of a broader regulatory push to tighten oversight of how telecommunications companies collect, share, and protect consumer data amid growing concerns about digital privacy and surveillance.