How the numbers on this site are derived, what's verified vs. estimated, and what's still missing.
All figures on this site are computed directly from the New York City Department of Finance's FY2027 Final Assessment Roll, specifically the raw Property Tax System (PTS) extract — not DOF's own published, rounded PDF summary tables. Source files: PROPMAST_TC1_2027_FIN.txt, PROPMAST_TC234_T2027_FIN.TXT. Because this site computes aggregates directly from the raw extract, figures here can run slightly higher or lower than DOF's own published FY2027 summary workbook; that's an expected, minor divergence between two independent tabulations of the same underlying records, not a data-quality problem.
A is DOF's basic unit of property assessment, identified by a unique BBL (borough digit + 5-digit tax block + 4-digit tax lot, e.g. 1008710031). Most tax lots correspond to a single building or parcel, but a large condo building is typically split into many tax lots — one per unit, each with its own BBL. This means unit-level condo data (like a 10-unit condo building) appears as 10 separate rows in the underlying data, each with its own market and assessed value.
DOF estimates market value for each tax lot using sales comparables, income capitalization (for rental/commercial property), or replacement cost, depending on property type. Assessed value is then derived from market value using each tax class's statutory assessment ratio and, for Class 1, an annual increase cap. See the Tax Classes page for the full breakdown of market vs. assessed vs. taxable vs. exempt value.
Individual people's names are never displayed anywhere on this site — not on the homepage, not in the Owners directory, not in search results, not in any API response. Only business, institutional, and government entities (LLCs, corporations, trusts, nonprofits, religious institutions, universities, hospitals, and government agencies) are shown by name. Everything else renders as "Private Owner."
This is enforced by a shared classification function (matching a curated list of entity suffixes/keywords like LLC, Corp, Trust, and government-agency phrases) that both the search API and every static page apply before any owner string is rendered — never as an after-the-fact UI filter on data that already left the server unredacted.
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| Source | Status | Note |
|---|---|---|
| DOF FY2027 Final Assessment Roll (PTS extract) | Available | Primary source for every figure on this site. |
| HCR rent-regulation registration files | Available | NYS HCR's 2024 building registration file (via NYC Rent Guidelines Board's official PDFs), joined by BBL at a 99.998% match rate (47,277 of 47,278 buildings). Building-level only — identifies buildings with ≥1 registered stabilized unit, not unit counts. |
| MapPLUTO (parcel coordinates) | Planned | Needed to power the interactive Map page — not yet joined to the roll. |
| Historical assessment rolls (prior fiscal years) | Planned | Would enable year-over-year trend views; only FY2027 is loaded today. |
| ACRIS (deed / sale transaction records) | Unavailable / manual | Would show actual sale prices vs. DOF market value; not currently in scope. |
| HPD (violations, code enforcement) | Unavailable / manual | Would add building-condition context; not currently in scope. |
| RPIE (income & expense filings) | Unavailable / manual | DOF's underlying income data for commercial valuations; not public at the lot level and not in scope. |