What is a BIN? NYC's building ID, explained

A BIN, or Building Identification Number, is the seven-digit number New York City assigns to each building. Addresses are ambiguous: corner buildings answer to multiple streets, complexes share one address across many structures, and street names repeat across boroughs. The BIN exists so every city record can point at exactly one structure, and it is the key that ties together most of the building data the city publishes.

How to read one

The first digit is the borough: 1 is Manhattan, 2 the Bronx, 3 Brooklyn, 4 Queens, 5 Staten Island. The remaining six digits identify the building within the borough. So 3037746 is a Brooklyn building, and every agency record carrying that BIN describes the same physical structure.

One caveat built into the system: numbers like 1000000, 2000000, and so on (a borough digit followed by six zeros) are placeholders meaning "borough known, building not identified". They appear on records where the address could not be matched to a structure. A record carrying a placeholder BIN belongs to a borough, not a building, and lookups treat it accordingly; this site excludes placeholder BINs rather than pile unrelated records onto a fake building.

BIN vs BBL

The city's other big identifier is the BBL: borough, tax block, and tax lot. The difference is what each one names. A BBL names a piece of land for tax purposes; a BIN names a structure. One tax lot can hold several buildings, each with its own BIN, and a single development can span lots. Property tax, ownership, and land records run on BBL; building-level records (violations, permits, inspections) mostly run on BIN. Many datasets carry both, which is how the two worlds join.

Where to find a building's BIN

Search the address on this site: the BIN is on the building's page and in its URL. The city's own address tools (City Planning's geocoding services, DOB's BIS, HPD Online) all return it too. Once you have the BIN, it is the most reliable search key there is: paste it into any city system or dataset and you get the building, regardless of how its address is spelled that day.

When the BIN changes

BINs are stable but not eternal. Demolish a building and its BIN retires with it; new construction gets a new number. A small number of records reference BINs that no longer stand, or that only ever existed inside an agency's paperwork, which is one of the honest gaps in city data: a violation can outlive the building it was written against. This guide is general information about public records.