On or before September 1 of each year the county treasurer shall send by mail to the last known address of each person or firm that owes delinquent taxes notice that there are delinquent taxes against the real property that is assessed in the taxpayer's name.
A.R.S. § 42-18103
Notice of delinquent taxes
Official source: Arizona State Legislature. Reproduced from public-domain Arizona statutes; confirm against the official source for the current text. Not legal advice.