How to Find Property Lines in New York
New York property owners have access to a rich set of public records and mapping tools to research their property boundaries. Online GIS viewers, county assessor databases, deed records at the county clerk, and the state's own GIS clearinghouse all provide useful starting points. None of them, however, replace a licensed surveyor when you need a legally defensible answer about exactly where your property lines sit.
This guide walks through the specific resources available to New York property owners, from free online tools to county clerk records, with direct references to the systems you can actually use today.
New York State GIS Clearinghouse
The New York State GIS Clearinghouse at gis.ny.gov is the state's central repository for geographic data. It includes parcel data layers for most New York counties, statewide orthoimagery, and access to county-level mapping resources. The clearinghouse is primarily a data resource for planners, researchers, and municipal agencies, but the parcel data it hosts is publicly downloadable and can be viewed in free GIS applications like QGIS.
For the average property owner, the most practical approach is to use the county-level GIS viewers linked through this system rather than downloading raw data files. The clearinghouse provides a directory of county-specific mapping resources that connect you to the right local tool.
County Assessor Parcel Viewers
Every county in New York maintains a parcel viewer through its assessor's or real property tax services office. These viewers display tax map parcel boundaries, ownership information, assessed values, and often aerial photography layers. They are searchable by address, owner name, or tax map parcel number.
Some of the most useful county parcel viewers in New York include:
- Albany County: Available through the Albany County Real Property Tax Service at albanycounty.com
- Erie County (Buffalo area): Erie County's parcel viewer at eriecounty.gov displays parcel boundaries with aerial imagery
- Monroe County (Rochester area): Monroe County's property search at monroecounty.gov includes GIS parcel mapping
- Nassau County: Nassau County's LESSA system at nasscounty.gov provides parcel mapping and assessment data
- Suffolk County: Suffolk County Real Property at suffolkcountyny.gov includes a parcel and mapping search
- Westchester County: Westchester County's GIS portal at westchestergov.com includes parcel data
To find your county's parcel viewer, search for your county name plus "parcel viewer" or "real property tax services." New York's 62 counties all maintain some form of online parcel data, though the sophistication and update frequency of each viewer varies.
NYC OASIS Map for New York City Boroughs
For properties within the five boroughs of New York City, the NYC OASIS (Open Accessible Space Information System) platform at oasis.citylimits.org provides an integrated mapping environment that includes tax lot boundaries, land use, zoning, and aerial photography. OASIS is built on NYC's PLUTO (Primary Land Use Tax Lot Output) database, which is one of the most detailed tax lot datasets in the country.
OASIS allows you to search by address, borough, block, and lot (BBL) number. It displays the tax lot outline overlaid on current aerial photography, which allows you to visually compare the mapped lot boundary to physical features on the ground. This is extremely useful for initial research, but the boundaries shown are derived from tax maps, not licensed surveys.
The NYC Department of City Planning also maintains a direct MapPLUTO data download at nyc.gov/site/planning/data-maps/open-data.page for users who need the full PLUTO dataset for analysis.
NYC Department of Finance - Tax Map
The New York City Department of Finance publishes the official NYC Tax Map online, which is the authoritative administrative map of tax lots within the five boroughs. The tax map is searchable by address and BBL and displays lot dimensions, block shapes, and in some cases, prior survey references. Access it through the NYC Department of Finance website at nyc.gov/finance.
The tax map is the most official approximation of property line locations in NYC, but it is still an administrative document. For legal boundary questions, it is a research tool, not a final answer.
County Clerk Deed and Plat Records
The county clerk in each New York county maintains the official record of all deeds, mortgages, and filed survey maps (plats). Reviewing these records is essential for understanding the legal description of a property's boundaries.
Many New York county clerks have digitized their records and made them searchable online. Search for your county's name plus "county clerk land records" or "deed search." Some counties use third-party platforms like Landex, iLinx, or their own custom portals.
In New York City, real property records are maintained by the NYC Office of the City Register (for Manhattan, Brooklyn, Queens, and the Bronx) and the Richmond County Clerk (for Staten Island). The ACRIS (Automated City Register Information System) platform at nyc.gov/acris allows free searching and document retrieval for NYC real property records including deeds and filed survey maps.
Reviewing your deed is the most direct way to find the legal description of your property's boundaries. Most modern New York deeds reference a filed subdivision map or contain a metes and bounds description. Understanding this description is key to any boundary research.
New York State Archives and Historical Records
For properties in older areas of New York where 19th-century or even earlier deed descriptions are involved, the New York State Archives in Albany can be a valuable resource. The Archives holds colonial land grant records, early land patent documents, and other historical records that predate modern county recording systems. For most routine property research, you will not need this level of historical depth, but it becomes relevant for rural parcels in the Hudson Valley, Mohawk Valley, or other areas with complex historical land title chains.
Limitations of Online Tools
All of the online and public records resources described above share a critical limitation: they show what the records say, not necessarily where the physical lines are on the ground. The gap between recorded documents and physical reality is often significant in New York for several reasons:
- Tax maps in New York were historically prepared from deeds and prior surveys, not from original fieldwork. They accumulate errors over time as they are updated from additional deed transfers.
- Older NYC neighborhoods contain lots where the tax map boundaries reflect administrative approximations rather than precise survey measurements.
- Rural parcels in upstate New York sometimes have deed descriptions that reference monuments that have been moved, removed, or never located with precision.
- Easements and encroachments that affect the practical use of a lot may not appear in tax map data at all.
When to Hire a Licensed New York Land Surveyor
Use the online resources to do your initial research: find your parcel number, pull the deed, look up the tax map dimensions, and review any filed surveys on record at the county clerk. This research will give you context and may answer basic questions about your lot's approximate size and shape.
But when the answer actually matters, such as before installing a fence, planning an addition, resolving a dispute with a neighbor, or buying property, hire a licensed New York land surveyor. Only a licensed surveyor can establish legal boundaries, set corner monuments, and produce a sealed survey map that carries legal weight.
To connect with a licensed surveyor near you, find a land surveyor in New York through our statewide directory covering all 62 counties.