Form RP-6604: Detail List of Changes Explained (NY State Tax Form)

Form RP-6604, officially titled “Detail List of Changes,” is a New York State Department of Taxation and Finance form used at the local assessment level to record every change made to a property’s assessment record after the tentative roll has been filed. Assessors and assessment offices rely on this document to create a clear, itemized paper trail whenever a property’s assessed value, exemption status, or ownership record is corrected between the tentative and final assessment roll.

Unlike forms that taxpayers fill out to request an exemption or challenge an assessment, RP-6604 is primarily an internal administrative document. It’s completed by assessing units — town, city, or county assessor offices — rather than by individual property owners. That said, homeowners and property tax professionals sometimes encounter it when reviewing how a change to their assessment was documented, or when requesting records related to a correction made to their property.

Who Needs to File Form RP-6604

The form is typically completed by:

• Town and city assessors making adjustments to assessed values after the tentative roll is published
• Assessment office staff processing corrections ordered by a Board of Assessment Review
• Local officials documenting clerical errors, exemption changes, or ownership updates before the final roll is certified

Because assessment rolls in New York move through several stages — tentative, grievance period, Board of Assessment Review, and final — RP-6604 exists to keep every modification transparent and traceable. This matters both for audit purposes and for taxpayers who want to understand exactly what changed on their parcel and why.

When This Form Is Used

RP-6604 comes into play any time a change is made to an assessment after the tentative roll has already been established. Common triggers include:

• A Board of Assessment Review decision that lowers or adjusts a property’s assessed value
• Correction of a data entry or calculation error discovered after the tentative roll was filed
• Updates to exemption eligibility that affect the taxable assessed value
• Court-ordered adjustments, which are sometimes cross-referenced with related documentation like the RP-6609 list of court-ordered adjustments

Assessing units generally need to keep this detailed list current throughout the roll cycle, since it becomes part of the official record supporting the final assessment roll submitted to the state.

How to Get and Complete the Form

Form RP-6604 is available as a fillable PDF directly from the New York State Department of Taxation and Finance website. Because it includes AcroForm fields, it can be filled out digitally on a computer using standard PDF software, then printed, signed, and filed according to local procedure — most assessing units still keep a printed, signed copy as part of the roll documentation, even after entering data electronically.

When completing the form, assessors typically need to provide:

• Parcel identification information (tax map number, owner name, property address)
• The prior assessed value and the corrected or revised value
• A brief explanation for the change (clerical error, BAR decision, exemption update, etc.)
• The date the change was made and the signature of the responsible assessing official

Assessors working with equalization data or reviewing how county-level rates interact with local roll changes may also want to reference Form RP-6584 on county equalization rates, since assessment corrections can influence how a municipality’s equalization rate is calculated for the year.

Property owners who are also dealing with STAR exemption reimbursement issues tied to a corrected assessment may find it useful to look at Form RP-6704-B1, which covers the STAR reimbursement application process for school tax levies.

Because RP-6604 feeds directly into how the final assessment roll is compiled, accuracy matters. Assessing units that keep this list well organized throughout the year typically have an easier time reconciling the tentative and final rolls, and they give property owners a clearer answer when questions come up about why an assessment changed.