Every Long Island property has a unique Section-Block-Lot (SBL) number. This is how Nassau and Suffolk assessment systems track parcels. You need it to look up your tax bill, file a grievance, or pay online. Here's how to find it.
Long Island uses a three-level parcel identifier:
A typical SBL looks like 123-04-006 or 32-J-061-00. Format varies slightly by county and town.
No. The deed reference is a separate record at the County Clerk's office, used for ownership history. The SBL is used for property tax purposes. Both refer to the same physical parcel.
Section, Block, Lot numbers occasionally get renumbered when a town subdivides a parcel, merges two parcels, or updates its tax map. If your SBL changed, the County will have records of the old and new identifiers tied together.
No. SBL is unique within each town/city. The full identifier across LI is "swis code + SBL" — the SWIS code identifies which town, so the combination is globally unique.
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Estimates and educational content only — not legal, tax, or financial advice. Verify with your county or town receiver, an attorney, or a CPA before making financial decisions.