40 CFR §60.2955

You must submit an annual report no later than 12 months following the submission of the information in § 60.2954, unless you choose to comply with the substitute means of compliance demonstration requirements in § 60.2929. If you choose to comply with the substitute means of compliance demonstration requirements in § 60.2929, you must submit an annual report no later than 12 months following the submission of the information in § 60.2929(b). You must submit subsequent reports no more than 12 months following the previous report. The permit will address the submittal of annual reports for a unit with an operating permit required under title V of the Clean Air Act.