Quick answerArizona sells tax lien certificates for unpaid property taxes. Lien buyers can earn Up to 16% per year, bid down — bidding starts at 16% and the lowest rate wins (0% bids allowed); interest is simple, a fraction of a month counts as a whole month (A.R.S. §§42-18053, 42-18114). Liens struck to the state earn the full 16%. Redemption: Owner may redeem at any time until a court judgment forecloses the right to redeem; the certificate holder may not begin judicial foreclosure until 3 years after the sale, and the lien expires if foreclosure is not commenced within 10 years (A.R.S. §§42-18152, 42-18201) Sales: Annual county treasurer tax lien sales in February Governing law: Arizona Revised Statutes Title 42, Chapter 18, esp. §§42-18053, 42-18112, 42-18114, 42-18152.