Service and filing

All pleadings, notices, written motions, requests, petitions, briefs, and correspondence to the commission or commission employees from a party, or vice versa, relating to a proceeding after its commencement must be filed with the director and entered into the commission's official record of the procedure provided the record is open at the time of receipt. All parties shall receive copies upon request of any evidence in the record of the proceedings. The commission may charge for the actual cost of providing copies of evidence in the record. Unless otherwise provided by law, filing is complete when the material is entered into the record of the proceeding.