Ariz. Tax Ct. R. P. 8
Rule 8. Tax Court Case Numbering
(a) Assigned Number. The Clerk's Office must assign a number to every case filed with or transferred to the Tax Court. (b) Prefix. (1) Small Tax Claims (“ST”). The Clerk's Office must number with the alphabetical prefix “ST” cases filed in the Tax Court as Small Claims Procedures under A.R.S. § 12-172 ; these cases are also called Small Tax Claims. (2) All Other Cases (“TX”). The Clerk's Office must number with the alphabetical prefix “TX” all tax cases other than Small Tax Claims.