Form RP-551-Ntc: Pro-Rated Tax and Omission Notice Form (New York)

Form RP-551-Ntc, officially titled “Pro-Rated Tax and Omission Notice,” is a notice form used by local assessors and tax offices across New York State. Unlike most Real Property Tax forms that a property owner fills out and submits, this one works the other way around: it’s generated by the assessing unit and sent to a property owner to inform them of a change in their assessment that affects their tax bill for a specific period of time.

This form falls under Article 5, Title 2 of the New York Real Property Tax Law, which deals with omitted assessments and pro-rated taxes. In plain terms, it’s used when a property was assessed incorrectly, left off the roll entirely, or needs a corrected valuation applied for only part of a tax year rather than the full year. That’s the “pro-rated” part of the name: instead of billing or refunding tax for a whole assessment period, the amount is calculated proportionally for the days or months affected.

Who Needs This Form

Form RP-551-Ntc is used by:

• Town, city, or county assessors who discover that a parcel was omitted from the assessment roll, or that improvements (like new construction or a completed renovation) weren’t reflected in the property’s assessed value on time.
• Property owners who receive this notice because their tax bill is being adjusted, either upward due to an omission or corrected downward due to an error found in the previous assessment.
• Local tax administrators who need a standardized, legally compliant way to document and communicate a pro-rated tax change to the taxpayer of record.

If you’re a homeowner or commercial property owner in New York and you receive this notice unexpectedly, it typically means your local assessor’s office has identified a discrepancy between what was on the roll and what should have been billed, and they are formally notifying you of the correction before it hits your tax bill.

When This Form Is Used

Assessors issue Form RP-551-Ntc in a few common situations. The most frequent is when a completed construction project, like a new addition or a finished basement conversion, wasn’t assessed for part of the year it should have been. Another common trigger is when a parcel was mistakenly left off the assessment roll altogether, sometimes due to administrative error during a parcel split, merger, or a data entry mistake following a sale or transfer. In both cases, the tax law allows the assessing unit to go back and apply an omitted or pro-rated assessment rather than waiting for the next full assessment cycle.

Because this notice deals with retroactive tax liability, it includes specific information: the assessed value being applied, the effective dates of the pro-rated period, the resulting tax amount, and instructions on how the property owner can respond or appeal if they disagree with the correction.

How to Get and Use This Form

Form RP-551-Ntc is available directly from the New York State Department of Taxation and Finance website as a fillable PDF, which means local assessing offices can complete it digitally before mailing or delivering it to the affected property owner. Since it’s a notice rather than an application, property owners generally don’t need to search for a blank copy themselves, they receive a completed version from their local assessor’s office.

That said, understanding the form matters. If you get one of these notices, read through the assessed value, the pro-ration period, and the total amount due or credited carefully before assuming it’s correct. Errors in omission and correction notices happen, and property owners have the right to question the calculation with their local assessor.

This form is part of a broader family of Real Property Tax System (RPTS) documents used by New York’s assessment community. If you’re dealing with related corrections, it may help to also review Form RP-5217ACR, which local assessors use to correct sale reporting data that can sometimes trigger omission notices in the first place. Assessors who need to submit related transmittal paperwork should also be familiar with Form RP-5217-App-1. And for those working within the assessment office system itself, Form RP-5100 covers the secure access request needed to work within ORPTS systems where these notices and corrections are generated.

If you have questions about a notice you’ve received, contacting your local assessor’s office directly is the fastest way to get clarity on the specific dates, values, and amounts listed on your copy of Form RP-551-Ntc.