What evidence do I need to grieve my New York assessment?

A New York grievance succeeds on evidence, and Form RP-524 is built around the two main proofs.

For an excessive-assessment claim — comparable sales. Gather recent, arm's-length sales of similar nearby homes (similar size, age, style, and location). If three comparable homes sold for around $360,000 and your assessment implies $420,000, the comps support a reduction. A recent purchase price of your own home (if you bought it close to the valuation date) or a fee appraisal is even stronger. Document these in Part Four of Form RP-524, which has a dedicated section for comparable sales.

For an unequal-assessment claim — the RAR. Use the published residential assessment ratio (RAR) for your municipality. Multiply your home's market value by the RAR to get an equitable assessment; if your actual assessment is higher, you are assessed unequally relative to other homes. Form RP-524 Part Four lets you support this with the RAR or with the assessments of comparable properties.

Factual errors are the easiest win. If the assessor's records show the wrong square footage, lot size, number of bathrooms, or condition, correcting the record can reduce the value with little argument. Bring the correct measurements or photos.

Presentation. You may submit everything in writing with the form and skip the in-person hearing, or appear before the Board of Assessment Review under RPTL §525 to walk through your comps. Keep it factual: state your claimed value, list each comparable with its sale price and date, and tie it to the reduction you seek per RPTL §524.

Don't rely on: asking-price listings, automated online estimates alone, or your tax bill being "too high" — the board wants sales and ratio data.