H&R Block sued the US Federal Trade Commission on Wednesday, seeking an order that could upend the agency’s case accusing the tax giant of misleading consumers about the scope of its free tax-filing services. The lawsuit in Kansas City, Missouri, federal court claims the FTC’s use of internal administrative law judges to hear cases violates the US Constitution. The FTC last month accused H&R Block of deceiving customers with broad marketing for “free” online tax filing services that really only apply to simple returns. The agency also said H&R Block had unfairly deleted consumers’ tax data. H&R Block has denied the FTC’s claims. A hearing before an administrative judge is set for Oct. 23. Wednesday’s lawsuit cites the power of US presidents enshrined in the Constitution to remove “inferior officers.” It says the FTC’s internal judges are improperly insulated from that authority, and that the agency must abandon their use. “The FTC could still vindicate its law-enforcement interests by conducting the adjudication itself,” the lawsuit said. H&R Block declined to comment on the lawsuit but said it “offers fair and transparent pricing.” The FTC did not immediately respond to a request for comment. The FTC’s administrative law judges preside over hearings and take evidence, and they issue findings that can be appealed to the full commission. The agency then hears arguments and issues a final order. Those decisions can be appealed to a US court. Federal agencies’ use of administrative law judges have been contested in other cases. The US Supreme Court in November heard a challenge to the US Securities and Exchange Commission’s similar proceedings using administrative law judges. The court’s ruling, expected by the end of June, could have broad consequences for such in-house agency tribunals.