Almost anyone who supplied labor, materials, equipment, or qualifying professional services to improve private real property and went unpaid can file a mechanics lien against that property. That includes general contractors, subcontractors down at least a tier or two, material suppliers, equipment rental companies, independent tradespeople, and in most states architects, engineers, and surveyors. The important exceptions sit at two edges: no one can lien government-owned property, and even an eligible claimant can lose the right by missing a notice deadline, working without a required license, or lacking a written contract where the state demands one.
Contractors and Subcontractors
A general contractor has the most direct path because they hold a contract with the owner. Work was performed under an agreement, payment was promised, and the property benefited. That direct relationship simplifies both the paperwork and the legal argument.
Subcontractors qualify too, even without a contract with the owner. A plumber hired by the general contractor, or a framing crew hired by the plumber, can file against the property if money stops flowing down the chain. Most states allow at least second-tier subcontractors — those hired by a first-tier sub — to file, and some extend rights further. The tradeoff is stricter notice rules. In many states, a subcontractor who fails to send a preliminary notice to the owner within a set number of days after starting work forfeits lien rights entirely.
A written contract is not always required. In roughly three-quarters of states, a contractor or subcontractor working under a verbal agreement can still file a valid lien if they can document the work with invoices, correspondence, photographs, or witness testimony. A handful of states require a written contract as a prerequisite, and several others impose the requirement only on specific project types like residential homestead work.
Material Suppliers and Equipment Lessors
Companies that supply lumber, concrete, steel, roofing materials, or other goods that become part of the finished structure can file a lien even if their workers never set foot on the jobsite. The property’s value increased because of those materials, and the supplier deserves to be paid for that contribution.
Equipment rental companies generally have the same right. If you lease an excavator, crane, or scaffolding system to a project and don’t get paid, you can lien the property in most states. The equipment doesn’t need to become a permanent part of the building; it just needs to have been used for the improvement.
There is an important boundary. Most states cut off lien rights for suppliers who sell materials to other suppliers rather than directly to someone working on the project. A steel mill that sells beams to a distributor, who then sells them to a framing contractor, typically cannot lien the property. The distributor can, because the distributor dealt directly with someone in the construction chain. This rule keeps the lien from reaching back to remote manufacturers with no real connection to the project.
Laborers and Independent Tradespeople
Individual workers who perform physical labor on a construction site can file liens in their own right. This includes electricians, welders, carpenters, and other skilled tradespeople operating as independent contractors or sole proprietors. Their claim rests on the most fundamental principle behind mechanics liens: physical work improved the property, and the person who did that work should be paid.
The distinction between an employee and an independent laborer matters here. An employee of a construction company generally looks to their employer for wages and would pursue a wage claim rather than a mechanics lien. An independent tradesperson hired to perform specific work can lien the property directly if they go unpaid. The line between these two categories follows the same tests used elsewhere in employment law: who controls the work, who provides the tools, and how the worker is paid all factor in.
Architects, Engineers, and Surveyors
Design professionals occupy a slightly more complicated space. Most states explicitly grant lien rights to architects, engineers, and land surveyors whose work contributes to a construction project. Their services add value to the property just as surely as framing or pouring concrete, and the statutes generally recognize that.
The wrinkle comes when a project never moves past the design phase. If an architect draws plans and the owner cancels before anyone breaks ground, the question of whether those plans “improved” the property gets murky. Some states allow the lien regardless, reasoning that a set of construction-ready plans increases the property’s development potential. Others require physical construction to have actually started before a design professional can file. A few states, including Alabama, Ohio, Kentucky, and Vermont, largely bar design professionals from lien rights altogether.
Who Cannot File: Government Projects
One category of claimant catches people off guard: anyone working on a government-owned project. You cannot file a mechanics lien against federal, state, or municipal property. Government land and buildings are immune from liens, full stop. A subcontractor who pours concrete for a new federal courthouse has zero lien rights against the property itself, no matter how much money is owed.
Congress addressed this gap with the Miller Act, which requires any contractor awarded a federal construction contract over $100,000 to post a payment bond before work begins.1Office of the Law Revision Counsel. 40 USC 3131 – Bonds The bond functions as a substitute for a lien. Instead of claiming against the property, unpaid subcontractors and suppliers file a claim against the bond, which is the exclusive remedy for parties seeking payment on federal projects.2U.S. General Services Administration. The Miller Act
Who can bring a bond claim, and how, depends on where you sit in the contracting chain. First-tier subcontractors and suppliers, with a direct contract with the prime contractor, can sue on the payment bond without giving advance notice. Second-tier claimants, who contracted with a subcontractor rather than the prime, must send written notice to the prime contractor within 90 days after their last day of work or final material delivery. Miss that 90-day window and the bond claim is gone. All bond claim lawsuits must be filed within one year of the claimant’s last work or delivery.3Office of the Law Revision Counsel. 40 USC 3133 – Right of Action and Jurisdiction
Every state has its own version of the Miller Act, commonly called “Little Miller Acts,” that impose similar bonding requirements on state and local public construction projects. The dollar thresholds, notice requirements, and claim deadlines vary by state, but the core concept is identical: bonds replace liens on public work.
What Can Still Disqualify an Eligible Filer
Having the right role on a project isn’t enough. Several administrative requirements can strip lien rights from someone who would otherwise qualify.
Licensing
Most states require contractors to hold a valid license, and operating without one when the law demands it can bar you from filing or enforcing a lien. Courts interpret these rules strictly. A contractor whose license lapsed for even a short period during the project has seen lien claims thrown out entirely. Some states allow unlicensed contractors to record a lien but prevent them from enforcing it through foreclosure, which makes the filing itself largely meaningless.
Business Registration
Many states require claimants to be registered as a business entity or to have filed certain documents before performing work. These are the kinds of administrative boxes that seem trivial until a court uses them to invalidate a six-figure claim.
Written Contract Requirements
A majority of states allow mechanics liens based on verbal agreements, but roughly half a dozen require a written contract as an absolute prerequisite. Several others require written contracts only for residential projects, homestead properties, or contracts above a certain dollar amount. When a written contract is required and doesn’t exist, the lien is dead on arrival regardless of how much work was performed or how clear the verbal agreement was.
Preliminary Notice
The most common way people lose lien rights is by missing a preliminary notice deadline. Most states require subcontractors and material suppliers to send a preliminary notice to the property owner within a set window after starting work, often 20 to 30 days. General contractors with a direct owner contract are sometimes exempt from this requirement, but lower-tier parties almost never are. Fail to send the notice on time and you’ve waived your lien rights, usually with no way to get them back.
Eligibility to file a mechanics lien is broad on paper and narrow in practice. The categories of people who can file cover almost everyone with a real financial stake in the improvement, but the rules that preserve those rights are unforgiving, and they vary enough from state to state that assumptions carried over from a neighboring jurisdiction are a reliable way to lose a valid claim. Confirm your state’s specific notice window, licensing rules, and contract requirements before the work begins, not after the payment stops.