How to File a Mechanics Lien in NY: Deadlines, Service, and Filing

To file a mechanic’s lien in NY, you prepare a verified Notice of Lien that meets the requirements of Lien Law § 9, file it with the County Clerk in the county where the property sits within four months of your last day of work on a single-family dwelling (or eight months for any other project), serve copies on the owner and on the party who hired you within a window running from five days before filing to thirty days after, and then file an affidavit of service with the County Clerk within thirty-five days of the original filing. Each of those steps has to land inside its own deadline. Miss one, and the lien is gone.

Who Can File

Lien Law § 3 opens the door to anyone who performed labor or furnished materials to improve real property, so long as the work was done with the owner’s consent or at the request of the owner’s agent, contractor, or subcontractor. General contractors, subcontractors, laborers, material suppliers, landscape gardeners, nurseries, and trust funds owed benefit contributions on behalf of laborers all qualify. Architects, engineers, and surveyors who provided design services for the improvement can file as well.¹

The connecting thread is a direct link between your work or materials and the improvement of a specific piece of property. Materials manufactured for a project but never delivered to the site still count as “materials furnished” under the statute.¹

The Filing Deadline

The clock starts on the last day you performed work or delivered materials, and how long you have depends on the property:

Single-family dwellings: four months from the last item of work or materials.
All other projects (commercial, multi-family, mixed-use): eight months from the last item of work or materials.
Retainage claims: ninety days from the date retainage was due to be released.

You can also file while work is still in progress.²

“Single-family dwelling” is narrower than it sounds. If the property is part of a subdivision filed with a municipality and is owned by a developer rather than a homeowner, it falls under the eight-month rule even though the building itself is a single-family home.²

There is no grace period. Miss the deadline and the right to file is gone.

What the Notice of Lien Must Say

Lien Law § 9 sets out what the notice has to contain. The notice must include:

Your name and address. Partnerships include partner names and the principal place of business; corporations include the business address and principal place of business, with an in-state address added for foreign corporations.
Your attorney’s name and address, if you have one.
The property owner’s name and their interest in the property, so far as you know it.
The name of the party who hired you or to whom you furnished materials. Contractors and subcontractors name the party they contracted with.
A description of the work performed or materials supplied, and the agreed price or value.
The unpaid amount.
The dates of your first and last items of work or delivery.
A property description sufficient for identification, including the street address if known. In cities or villages, include the street and number. In counties that use a block index system, include block and lot numbers.
Whether the property is a single-family dwelling, which affects deadlines and extension rules.

Getting the owner’s name wrong or misdescribing the true owner will not, by itself, invalidate the lien.³

Verification

The notice has to be verified. You or your agent signs a sworn statement that the contents are true to your knowledge, except for matters stated on information and belief, which you believe to be true. In practice, that means a notarized oath. An unverified notice is not a valid lien.³

State the Amount Honestly

Under Lien Law § 39, if a court finds you willfully exaggerated the lien amount, the entire lien is declared void and you recover nothing. You also lose the right to file any future lien for the same claim. An honest mistake or minor inaccuracy will not trigger the penalty; deliberate inflation will.⁴

Section 39-a lets an owner or contractor who proves willful exaggeration recover damages, including reasonable attorney’s fees for getting the lien discharged, the cost of any bond premium paid to clear the property, and the difference between the claimed and actual amount owed.⁵

Filing With the County Clerk

File the completed, verified notice with the County Clerk in the county where the property is located. If the property crosses county lines, file in each county.²

Filing fees vary by county but are generally modest. Expect a recording fee for the notice and a smaller fee for the affidavit of service you’ll file later. Some County Clerks sell blank lien forms; you can also prepare your own as long as it meets § 9. Bring the notice ready to record, with block and lot numbers filled in wherever the county uses a block index.

Serving the Notice

Filing alone is not enough. You have to serve copies on the right people and prove you did. This is the step that kills more liens than any other.

Who Gets Served, and How

Serve a copy of the filed notice on the property owner within a window that runs from five days before filing to thirty days after. For an individual owner, you can deliver the notice personally, leave it with a person of suitable age at the owner’s residence in the city or town where the property is located, or send it by certified or registered mail to the owner’s last known address. For a corporation, deliver the copy to an officer, director, or managing agent, or send it by certified mail to the corporation’s last known place of business.⁶

Lien Law § 11-b requires you to also serve a copy by certified mail on the contractor, subcontractor, or other party who hired you or received your materials. If your contract is with a subcontractor and not the general contractor, serve both. The same five-days-before to thirty-days-after window applies.⁷

Skipping service on the hiring party has an extra cost: § 11-b makes you liable for the other side’s reasonable attorney’s fees and costs incurred in obtaining a copy of the notice on their own.⁷

The 35-Day Affidavit of Service

After serving the notice, file an affidavit of service with the County Clerk within thirty-five days of the date you filed the original notice. Sections 11 and 11-b both state that the lien terminates automatically if you miss this deadline, even if service itself was flawless.⁶⁷

Keeping the Lien Alive

A mechanic’s lien is valid for one year from the filing date. After that, it expires unless you take action.⁸

You have two ways to prevent expiration:

File a foreclosure action. Start a lawsuit to enforce the lien and file a notice of pendency with the County Clerk before the one-year mark. The notice of pendency must include the parties’ names, the purpose of the action, a property description, and the date the lien was filed.
File an extension. For properties other than single-family dwellings, you can file an extension with the County Clerk within the original one-year period. The extension keeps the lien alive for one additional year. Any further extension requires a court order.

Single-family dwellings work differently. You cannot extend the lien by filing paperwork with the County Clerk. Even the first extension requires a court order.⁸

If the extension period ends without a foreclosure action or a court-ordered extension, the lien is extinguished.

Public Projects Follow Different Rules

Everything above concerns private improvements. Liens on public projects are filed with the public agency that contracted for the work, not the County Clerk. In New York City, liens against mayoral agency projects are filed with the NYC Department of Finance, while authorities such as the Transit Authority, Housing Authority, and School Construction Authority handle their own liens directly.⁹

Deadlines are tighter. For public improvement projects in New York City, the notice must be filed before the project is completed or within thirty days of the date the agency accepts the project, regardless of when your particular work ended.¹⁰ Outside New York City, filing locations and acceptance procedures vary by agency, so confirm both with the contracting agency before your window closes.

Mistakes That Void the Lien

The mechanics are straightforward on paper and unforgiving in practice. The errors that come up most often:

Missing the four-month or eight-month filing deadline. Calendar the last day of work as soon as it happens and set a reminder well before the cutoff.
Filing an unverified notice. Have it notarized before you take it to the County Clerk.
Missing the thirty-five-day affidavit of service. Perfect service does not save a lien if proof of service is filed late.
Serving the owner but forgetting the contractor. Section 11-b requires service on the hiring party and shifts attorney’s fees to you if you skip it.
Inflating the amount. Willful exaggeration voids the lien under § 39 and exposes you to damages under § 39-a.

A checklist and a calendar prevent most of these. The lien is a strong remedy, but only when every step lands inside its window.

1
New York State Senate. New York Code LIE 3 – Mechanic’s Lien on Real Property
2
New York State Senate. New York Lien Law 10 – Filing of Notice of Lien
3
New York State Senate. New York Code LIE 9 – Contents of Notice of Lien
4
New York State Senate. New York Code LIE 39 – Lien Wilfully Exaggerated Is Void
5
New York State Senate. New York Code LIE 39-A – Liability of Lienor Where Lien Wilfully Exaggerated
6
New York State Senate. New York Code LIE 11 – Service of Copy of Notice of Lien
7
New York State Senate. New York Lien Law LIE 11-B
8
New York State Senate. New York Lien Law LIE 17 – Duration of Lien
9
NYC311. Public Improvement or Mechanic’s Lien
10
NYC Department of Finance. Public Improvement Lien (Mechanic’s Lien)