Updated September 7, 2026. Before preparing a New York mechanic's lien, assemble the project records and identify the procedure that applies. A county clerk's acceptance of a form does not establish that the claim is enforceable.
Identify the project and claimant
Confirm whether the improvement is private or public, the owner's legal name and interest, the property description, your contracting party and your place in the contracting chain. Check any applicable local licensing requirements. Corporations and partnerships should address the business-identification requirements in the applicable statute, including the requirements for a foreign corporation.
Prepare an accurate claim file
Gather the contract, change orders, invoices, delivery records, payment history and first and last qualifying work dates. Reconcile credits and payments before calculating the amount. Separate amounts supported by lienable work or materials from other contract damages.
Lien Law § 9 specifies the contents and verification of a private-improvement notice, including claimant and contracting-party information, work or materials, unpaid amount, dates and property identification. Do not assume every clerical error automatically invalidates a lien: some issues involve substantial compliance or amendment under § 12-a. Equally, do not assume an expired or substantively defective lien can always be repaired.
Calculate the filing deadline separately
Under § 10, most private-improvement liens have an eight-month filing period measured from the relevant last work or materials. The usual period for a single-family dwelling is four months. These are calendar months; four months is not a fixed 120-day period.
The single-family definition excludes certain developer-owned dwellings in a subdivision filed with the municipality, where the statutory ownership and common-development-plan conditions are met. Section 10 also provides a 90-day period after retainage was due to be released for a lien for retainage. Evaluate those provisions against the actual project rather than assuming an exception applies.
A public-improvement lien uses different filing offices and requirements. Under § 12, it may be filed before the improvement is completed and accepted, and within 30 days after completion and acceptance. Do not substitute the date of your last invoice for that statutory event.
Plan service and proof before filing
For a private lien, § 11 addresses service on the owner within five days before or 30 days after filing. § 11-b requires certified-mail service on the specified contracting party and, for certain lower-tier claimants, the contractor. File the required proofs of service within 35 days after filing the lien. Public liens have their own service procedure under § 11-c.
Calendar the next step immediately
A private lien generally lasts one year unless properly continued. Under § 17, a first non-single-family extension may be filed; further extensions require court action. Single-family extensions require a court order. Foreclosure, notices of pendency and liens discharged by bond or deposit have additional requirements. Negotiations do not automatically keep a lien alive.
Kushnick Pallaci PLLC assists with mechanic’s lien preparation and disputes and lien foreclosure and defense. Call 631-752-7100 or see the firm’s current contact information.
The firm provides further information on filing a New York mechanic's lien and extending a lien.
This checklist is general information, not a completed filing or a deadline calculation for a particular claim.