Property tax is the largest tax most homeowners pay that nobody checks, and the number on the notice is an opinion rather than a fact. This article explains how an assessment is actually produced, why the assessed value is frequently not the market value, and how the millage rate turns one into a bill. It then walks through the two independent grounds for appeal — overvaluation and lack of uniformity with comparable properties — and shows with worked numbers how each is proved and which one is usually easier to win. Separate sections cover the exemptions and credits that go unclaimed for years, the mortgage escrow analysis that turns a modest increase into a payment shock, and the tax lien and tax deed process that can take a house over a small debt. The constitutional limits are covered, including the notice requirements for a tax sale and the surplus proceeds rule that recently changed the landscape. Practical sections explain the evidence that actually persuades a board of review and the calendar that governs everything. Every authority is linked to its text.