Learn NYC property · Agencies and the basics

PLUTO, NYC Open Data and the public registries behind a property

What NYC Open Data is, what City Planning's PLUTO lot file holds and where its fields come from, how city-owned land is marked, what the New York Department of State's business registry says about the companies that own buildings — and how BlockLot uses each.

Almost everything BlockLot knows about a property comes from records New York's governments publish themselves. Three sources do most of the work: NYC Open Data, where City agencies publish their records as data; PLUTO, City Planning's file of every tax lot; and the New York Department of State's registry of companies, which says who stands behind an owner that is an LLC or a corporation.

NYC Open Data

NYC Open Data is the City's portal for the data its agencies keep — violations, permits, sales, the tax roll, 311 calls and thousands of other datasets — free to download or query, with no registration. Each agency has an Open Data Coordinator who publishes and maintains its datasets, and the program is run by the City's Office of Data Strategy. The datasets can be read through an API as well as downloaded.

The Open Data Law, Local Law 11 of 2012, enacted on March 7, 2012, requires City agencies to publish their public data on a single web portal, in formats a computer can read, with no registration or restriction on use. Local Law 251 of 2017 added agency coordinators, a master list of every public dataset and a yearly compliance report each September. The law also says the City does not warrant the data's accuracy: the agency that keeps a record remains the place to check it.

PLUTO

PLUTO — the Primary Land Use Tax Lot Output — is the Department of City Planning's file of every tax lot in the city, with more than seventy fields for each. It joins what several agencies know about a lot into one row: from the Department of Finance, the owner, lot size, building class, units, year built and assessed value; from City Planning, the zoning and the political and administrative districts; from the Department of Citywide Administrative Services, City ownership; from the Landmarks Preservation Commission, landmarks and historic districts.

The agencies whose records PLUTO joins, lot by lot.

City Planning releases a full update every quarter and a zoning-only update each month in between; the current version on October 9, 2026 is 26v2, dated August 2026. Each release is named by year and number, and its README lists the date of every source it was built from.

PLUTO lists a condominium once, under its billing lot, with the units' residential count added up — so PLUTO's count of lots is smaller than the Department of Finance's roll, which lists every condominium unit. BlockLot holds 858,982 PLUTO lots; BBL, block and lot explains billing and unit lots.

MapPLUTO is PLUTO joined to the Department of Finance's digital tax map, so each lot has its shape for mapping. Lots that are wholly or partly under water are clipped to the shoreline, and the few records with no shape on the tax map are published in a separate table.

What PLUTO is good for, and its limits

PLUTO answers the questions about a lot that no single agency does: how big it is, what stands on it, what zoning allows there, which districts it is in. City Planning is careful about its limits:

Year built is accurate to the decade, not necessarily the year: between 1910 and 1985 most values end in 0 or 5.
Built floor area ratio is an estimate from rough measurements of building and lot area.
Lot area can include the bed of a street that was mapped but never built.
City Planning edits some values, flags each edited lot, and gives no warranty for the file's completeness or accuracy.

A worked example. On PLUTO, the Empire State Building's lot has building class O4 and land use "Commercial and office buildings"; 102 floors on a lot of 91,351 square feet, with 2,812,739 square feet of floor area; built in 1931; and it sits in Manhattan Community District 5 and City Council District 4.

City-owned property

PLUTO's owner type says who owns a lot when it is not an ordinary private owner. City Planning takes it from the City's own list of the property it owns and leases, and from the tax roll:

Code	Means	Lots
C	City-owned	13,015
M	Mixed City and private	77
O	Public authority, State or federal	1,406
X	Fully tax-exempt, any owner	20,497

The counts are BlockLot Intelligence's, from PLUTO. A blank means the owner type is unknown, which is usually a private owner. City Planning advises checking the owner's name too, especially to tell State, federal and public-authority land apart.

The list behind the codes is COLP, City Owned and Leased Properties, which City Planning publishes as the City Charter requires, from the Department of Citywide Administrative Services' property database. It records each agency's use of each lot the City owns or leases and is released every six months.

The New York Department of State

When a building's owner is a company, the New York Department of State (NY DOS) is where the company is registered. Its corporation and business entity database lists every corporation, limited liability company and partnership formed or registered in New York, each under a DOS ID, with its name, the date it was formed, its county, its status — and an address for legal papers.

The DOS process address is that address. By law the Secretary of State is the agent for service of process for every LLC and corporation, and forwards legal papers to the address the company gave. BlockLot calls it the company's registered office. It is a mailing address the company chose, and the State warns that it may not be where the business actually is.

A company may also name a registered agent, a person or firm that accepts legal papers on its behalf in New York; the database shows one only if one was designated.

What the registry does not hold matters as much: the Department of State keeps no list of a company's officers, directors, members or managers. An LLC must also publish notice of its formation in two newspapers within 120 days, or lose its authority to do business until it does.

The LLC Transparency Act requires some LLCs to report the people who own or control them, but the reports are confidential, not public. Since January 1, 2026 it has applied only to LLCs formed in a foreign country and registered to do business in New York; LLCs formed in New York or another state are exempt, and companies already registered must file by the end of 2026. The State's published list of active entities held 4,295,636 of them in October 2026, 2,062,287 of them New York LLCs.

How BlockLot uses them

BlockLot copies these records from their publishers and keeps them whole, then joins them on the lot's BBL: PLUTO's lot and building facts, the Department of Finance's roll and sales, ACRIS's deeds and mortgages, HPD's and DOB's violations, permits and registrations. Where the owner is a company, BlockLot matches its name to the Department of State's registry to find its process address and the other companies registered there — a match on names, which BlockLot shows as its own reading of the record, not the State's. Every figure in these guides is computed from the same records, as BlockLot Intelligence explains.

Where you see this in BlockLot

A building's Lot & building card is PLUTO's row for the lot, as its heading says; a company owner's page shows its Department of State registration — the DOS ID and the address for legal papers — beside the buildings it holds; and a City-owned lot says so in the Owner card.

The Lot & building card is PLUTO's record of the lot.
PLUTO, the source of the card
PLUTO's year built — right to the decade

Questions people ask

What is PLUTO? City Planning's file of every tax lot in New York City, joining the Department of Finance's tax records with zoning, districts, landmarks and City ownership — more than seventy facts per lot, free on NYC Open Data.

How often is PLUTO updated? A full release every quarter, and a zoning-only update each month in between. Each release names the dates of the sources it was built from.

Is NYC Open Data free? Yes. The Open Data Law requires City agencies to publish their public data with no registration or restriction on use.

How do I find out who owns an LLC? The State's business registry gives the LLC's address for legal papers, but not its members or managers; New York does not publish them. For a rental building, HPD's registration names the owner's officers, and the recorded documents in ACRIS show who signed them.

How do I know whether a lot is owned by the City? PLUTO's owner type marks City-owned lots with a C, from the City's own list of the property it owns and leases.

Why is the year a building was built sometimes wrong? Because the year in the City's records is often an estimate: City Planning says it is accurate for the decade, not necessarily the year.

BBL, block and lot: how New York numbers its land and buildings — What a BBL is, how borough, block and lot make up its ten digits, why condominiums have billing lots and unit lots, how lots are merged and split, and how the BIN that identifies a building differs.
Building class codes and land use: what A1, C6, D4, O4 and R4 mean — How the Department of Finance's two-character building class describes every property in New York City, the 25 letter families from A to Z, the codes beginners meet most, how a building class relates to the tax class, and City Planning's eleven land-use categories built from it.
BlockLot Intelligence: how our figures are made — Where the live counts and timeframes in BlockLot's guides come from — the public records they are computed from, how often they are refreshed, how a waiting time is measured, and what the numbers can and cannot tell you.
Department of Finance (DOF) — What New York City's Department of Finance does for property — the yearly assessment roll, the property tax bill and its calendar, the City Register that records deeds and mortgages, the transfer taxes, exemptions and the charges other agencies put on a property's account.

Sources

By BlockLot. Reviewed October 9, 2026. Figures by BlockLot Intelligence, computed from public data on October 11, 2026. This page explains the rules in general; it is not legal or tax advice. For a decision about a specific property, check the official source or ask a professional. Spotted a mistake? Tell us.