47 C.F.R. §§ 1.716–1.718

An informal complaint shall be in writing and should contain: (a) The name, address and telephone number of the complaint, (b) the name of the carrier against which the complaint is made, (c) a complete statement of the facts tending to show that such carrier did or omitted to do anything in contravention of the Communications Act, and (d) the specific relief of satisfaction sought.

The Commission will forward informal complaints to the appropriate carrier for investigation and may set a due date for the carrier to provide a written response to the informal complaint to the Commission, with a copy to the complainant. The response will advise the Commission of the carrier's satisfaction of the complaint or of its refusal or inability to do so. Where there are clear indications from the carrier's response or from other communications with the parties that the complaint has been satisfied, the Commission may, in its discretion, consider a complaint proceeding to be closed. In all other cases, the Commission will notify the complainant that if the complainant is not satisfied by the carrier's response, or if the carrier has failed to submit a response by the due date, the complainant may file a formal complaint in accordance with § 1.721.

When an informal complaint has not been satisfied pursuant to § 1.717, the complainant may file a formal complaint with this Commission in the form specified in § 1.721. Such filing will be deemed to relate back to the filing date of the informal complaint: Provided, That the formal complaint: Is filed within 6 months from the date of the carrier's response, or if no response has been filed, within 6 months of the due date for the response; makes reference to the date of the informal complaint, and is based on the same cause of action as the informal complaint. If no formal complaint is filed within the 6-month period, the informal complaint proceeding will be closed.