D.C. Code § 34-1123: Schedule of rates to be filed; existing rates to remain in force until changed.

Every public utility shall file with the Commission, within a time to be fixed by the Commission, schedules, which shall be open to public inspection, showing all rates, tolls, and charges which it has established and which are in force at the time for any service performed by it within the District of Columbia, or for any service in connection therewith or performed by any public utility controlled or operated by it. The rates, tolls, and charges shown on such schedules shall not exceed the rates, tolls, and charges allowed by law on March 4, 1913, and shall be the lawful rates, tolls, and charges within the District of Columbia, and shall remain and be in force until set aside by the Commission.