What is a BBL?

BBL stands for Borough, Block, Lot - a 10-digit number used by New York City to identify tax lots. It is often the most reliable way to match the same property across city systems, even when address labels differ.

BBL Format

A BBL consists of 10 digits in the format: B BBBBB LLLL

First Digit (B)

Borough Code:

1 = Manhattan
2 = Bronx
3 = Brooklyn
4 = Queens
5 = Staten Island

Next 9 Digits

Block and Lot Number:

Digits 2-6: five-digit block number
Digits 7-10: four-digit lot number
Leading zeroes are part of the identifier

Example: 3076320045

3 = Brooklyn
07632 = Block 7632
0045 = Lot 45

Why BBLs Matter

Official Records

Many NYC property records, including supported violations, permits, tax, and agency datasets, can be organized around a BBL

Unique Identification

BBLs help match the same tax lot across city systems even when street names or address labels differ

Data Integration

Helps connect supported public records from multiple NYC agencies to the same property key

Plain-English Source Labels

A BBL helps you compare the same tax lot across different NYC systems. Each system has its own purpose, timing, and labels, so a missing result in one place should not be treated as proof that no official record exists.

PIP and ZoLa

NYC map and property-reference tools used to verify borough, block, lot, address, zoning, and related parcel context.

DOF

Department of Finance records such as tax and property identifiers.

DOB

Department of Buildings records such as permits, filings, jobs, and some building-related enforcement context.

HPD

Housing Preservation and Development records such as registrations, complaints, violations, and housing-maintenance context.

OATH

Office of Administrative Trials and Hearings records such as summonses and hearing-related enforcement context.

ACRIS

City Register records such as deeds, mortgages, and other recorded property documents.

311

Public service request records that may describe reported conditions, not official conclusions about a property.

What a BBL Page Can and Cannot Tell You

Can help with

Checking a stable property identifier, comparing source labels, following official links, and collecting better questions for review.

Cannot prove

That every source has been checked, that missing public preview rows mean no official records exist, or that a property has a legal, tax, title, safety, investment, or compliance conclusion.

Finding BBLs

NYC DOF NOW

Search by address to find BBLs through NYC's Department of Finance portal

Property Records

Check property tax bills, deeds, or other official documents

PropSignal Search

Use our BBL search to look up properties and start monitoring

BBLs in Property Monitoring

PropSignal uses BBLs as the foundation for property monitoring:

Violation Tracking - supported HPD and DOB records tied to specific BBLs
Permit Monitoring - supported DOB permit and filing context for properties
Tax Lien Detection - supported tax-lien context affecting specific parcels
Change Updates - Property record changes where supported