This guide covers the entire tax sale process from the first missed installment through a surplus distribution or a quiet title judgment. It explains the two statutory systems and how to tell which one governs a parcel. It sets out the redemption computation in detail, including the accruals owners consistently underestimate. It covers the constitutional notice requirements that most successful challenges rest on and the short deadlines that defeat them. It explains the surplus rule after the 2023 Supreme Court decision, who is paid in what order, and how to make the claim. It treats federal tax liens, bankruptcy timing, deceased owners, and heir property as separate problems requiring separate analysis. It closes with a purchaser's diligence protocol and a prevention program for owners.