If so authorized by an insurer that is a member or subscriber of a rating organization, the commissioner shall accept, in lieu of filings by the insurer, form and rate filings on its behalf made by a rating organization then licensed as provided in this chapter. Rate filings accepted by the commissioner become effective only as provided in RCW 48.29.147. Form filings accepted by the commissioner become effective only as provided in chapter 48.18 RCW.