Filings are made at the Arizona Corporation Commission's Docket Control Office. The address is 1200 W. Washington Ave, Phoenix, Arizona 85007. However the ACC's entrance and parking are in the rear of the building off Adams Street, which is one block north of Washington Avenue. There is a second ACC office at 1300 W. Washington Avenue, but this is for corporate and security filings.
For most cases you must file an original and 13 copies. It is important to make a good first impression. If your filing is large, organize your copies in binders with tabs. These will be circulated to the Commissioners, Hearing Division, and Staff. However, your original will be scanned, so do not three-hole punch it, insert dividers and tabs, or place it in binders. Filings made in the morning will typically be available on eDocket later that day. Filings made later in the day will not normally be available on-line until the next day.
For a new case that may affect residential rates, I recommend that you provide an extra copy of you filing to the Residential Utility Consumer Office. The office is next door on the second floor of the building housing the Arizona Department of Environmental Quality, 1110 W. Washington, Suite 220, Phoenix, AZ 85007
See genererally, Arizona Revised Statutes - Title 40 (A.R.S. § 40-101, et. seq.); Arizona Administrative Code - Title 14, Ch. 2. (R14-2-101, et. seq.) Rules for Fixed Utilities; and R14-3-101, et. seq. Rules of Arizona Practice and Procedure. Also, check the ACC web site for additional filing requirements. For example, for a water rate-case application, check the Commission's website here.