Overview
A BBL (Borough-Block-Lot) number is a unique 10-digit identifier assigned to every tax lot in New York City. It consists of three components: Borough (1 digit), Block (5 digits), and Lot (4 digits). This numbering system is the foundation of NYC property records and is used by virtually every city agency.
BBL Components
- Borough - A single digit identifying the borough: 1 = Manhattan, 2 = Bronx, 3 = Brooklyn, 4 = Queens, 5 = Staten Island
- Block - A five-digit number identifying the tax block (a group of lots bounded by streets)
- Lot - A four-digit number identifying the specific lot within the block
How BBLs Are Used
The BBL is the primary key for cross-referencing property data across NYC agencies. DOB, HPD, DOF, ACRIS, and other agencies all use BBLs to identify properties. When searching for property information, using the BBL ensures you get results for exactly the right property, avoiding address formatting issues.
Finding a BBL
You can find a property BBL through the DOF property tax portal, ZoLa mapping tool, or by searching any property on RegWatch. The BBL appears on tax bills, DOB permits, and most agency records. It is also the most reliable way to search ACRIS for property documents.
Condo BBLs
Condominium units have their own lot numbers within the building block. The common areas of a condo building typically have lot number 1001 or similar, while individual units have sequential lot numbers. This distinguishes condos from co-ops, where the entire building shares a single BBL.
Why It Matters
Using BBLs ensures accuracy when researching properties. Addresses can be ambiguous (different agencies format them differently), but a BBL is unambiguous. For professionals doing title searches, due diligence, or compliance work, the BBL is the standard identifier.
Frequently asked
What does BBL stand for?
BBL stands for Borough-Block-Lot. It is a 10-digit number (1 borough digit + 5 block digits + 4 lot digits) that uniquely identifies every tax lot in New York City.
How do I find the BBL for a property?
You can find a BBL through the NYC DOF property tax portal, ZoLa mapping tool, or RegWatch. It also appears on property tax bills, DOB records, and most agency documents.
Do co-ops have BBLs?
Co-op buildings have a single BBL for the entire building. Individual co-op units do not have separate BBLs because co-op ownership is shares of a corporation, not real property. Condos, by contrast, have individual BBLs per unit.
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