Filing deadline

Private jobs: file the notice of lien with the county clerk where the property lies any time during the work and up to 8 months after the claimant's own contract completion/final furnishing; single-family dwellings get only 4 months. Broker-commission liens: 8 months from lease execution. Public jobs: file with the department head and the state comptroller/fiscal officer before, or within 30 days after, completion and acceptance. Warranty or punch-list work does not extend the clock.

Notice prerequisites

No preliminary or pre-work notice from any tier; the notice of lien itself is the first required filing. (Lenders, by contrast, must record the building loan contract/mortgage with a trust-fund covenant to beat later liens.)

Service on the owner

Private lien: serve a copy on the owner, and by certified mail on the party that hired the claimant (plus the GC if the claimant contracted with a sub or sub-sub), within a window of 5 days before to 30 days after filing; proof of service must hit the county clerk within 35 days of filing or the lien terminates. Public lien: the same certified-mail service must occur 5 days before or simultaneously with filing, and the filed lien must contain proof of service or it is a nullity.

Enforcement

Both private and public liens expire 1 year after filing unless a foreclosure suit is started or the lien is extended (one filing extension for non-single-family private liens; otherwise court order, max two successive 1-year extensions). A Notice of Pendency (lis pendens) must be filed before the lien expires - private with the county clerk (3-year life, extendable but never refileable), public with the fiscal officer (does not expire). A demand to commence suit can shorten the year.

N.Y. Lien Law sec. 3, 5, 9-13, 17-21, 23, 34, 39-a, 44, 56, 70-79-a