The notice itself is the starting point every time, because it carries both the assessed value being challenged and the exact date the window closes. Missing that date usually means waiting for next year's notice rather than getting a mid-year hearing.
Once filed, the board hears evidence, most often recent comparable sales from Saskatchewan REALTORS Association data, and decides whether the assessed value should change. A stronger filing shows several comparables, not one favourable outlier, since residential property is taxed on 80 percent of assessed value and a small correction there still moves the bill.
Most owners only go through this once every few years, which is exactly why it is worth doing carefully the one time it matters. Get your hand-reviewed valuation from Joel Dyck.