The most expensive misunderstanding in early-stage hiring is the belief that calling someone a contractor makes them one. It does not. Classification is decided by legal tests that examine the actual relationship, and the tests are applied by agencies and courts that have seen every version of the artful label. A startup can get away with the mislabel for years, and then a funding round, an exit, a state audit, or one unhappy worker makes the whole history due at once.
This guide covers the tests that decide classification, the current federal enforcement picture, what misclassification really costs, and the separate trap founders miss: even a correctly classified contractor owns their work product unless the paper says otherwise. That second issue connects directly to who owns the code a contractor writes.
Why startups default to contractors
The reasons are rational: no payroll taxes or benefits, easy start and stop, budget clarity, and access to specialists you could never hire full time. Contractors are a legitimate and often correct tool. The problem is not using contractors; it is using contractor paperwork for what is functionally an employment relationship, because every incentive in the early company pushes that direction and nothing pushes back until the stakes are high.
The tests that actually decide
Three families of tests matter, and the strictest one that applies to you wins.
- The IRS common-law test asks who controls the work: behavioral control (who decides how, when, and where), financial control (who provides tools, whether the worker has other clients and real profit-or-loss exposure), and the nature of the relationship (permanency, benefits, how central the work is).
- Federal wage law (the FLSA) uses an economic-reality inquiry: is this worker in business for themselves, or economically dependent on your company? The enforcement posture here recently shifted. In May 2025 the US Department of Labor announced it would not enforce the stricter 2024 classification rule while it reconsiders, returning its enforcement to the older, more flexible framing. Two cautions belong next to that sentence: the 2024 rule remains on the books and can still be invoked by private plaintiffs, and enforcement positions can change again with administrations.
- State tests, led by the ABC test. California and several other states presume employment unless the company proves all three prongs: freedom from control, work outside the usual course of the company's business, and an independently established business. Prong B is the startup killer. An engineer building your core product, on your roadmap, in your repo, is doing the usual course of your business, and no invoice format changes that.
The practical rule that falls out: build to the strictest test you touch. If you have workers in an ABC-test state, or your own company sits in one, the federal softening does not save you.
The invoice does not decide. The relationship decides, and the strictest test that touches the relationship is the one a regulator will use.
What getting it wrong costs
Misclassification is expensive in an unusually layered way: back employment taxes with penalties and interest, retroactive minimum wage and overtime, benefits the worker should have received, unemployment and workers' compensation contributions, and per-worker statutory penalties in some states. Then the second layer: private lawsuits, including class actions where several contractors were treated alike. Then the third, quieter layer: diligence. Investors and acquirers ask how many contractors you have and what they do, precisely because inherited misclassification liability is real money. A cap table can survive it; a closing timeline sometimes cannot.
The IP trap inside every contractor relationship
Classification and ownership are different problems, and the second one bites even when the first is handled. Founders assume that paying for work means owning it. For contractors, the default rule is roughly the opposite: the work-for-hire doctrine is narrow, most software does not qualify, and absent a written assignment the contractor can retain ownership of the thing you paid them to build. The fix is simple and non-negotiable: present-tense assignment language ("hereby assigns") in every contractor agreement, and a proprietary information and invention assignment agreement (PIIA) for every employee, signed at the start, not collected in a panic before a financing. The full mechanics, including the one-word drafting mistake that undoes assignments, are in who owns your startup's code.
A practical playbook for early teams
- Use contractors for genuinely independent work: defined projects, their own tools and methods, other clients, invoiced deliverables. Design the relationship to be what the paper says.
- Write real contractor agreements: scope, deliverables, payment, IP assignment, confidentiality, and independent-contractor mechanics (no benefits, own taxes, right to work for others).
- Watch the drift. The dangerous case is the contractor who slowly becomes full-time, on your standup, on your schedule, only your client. Relationships drift; classifications do not drift with them. Re-examine quarterly.
- Convert when the role becomes core. When someone is doing the usual course of your business on your direction, put them on payroll. It costs more per month and enormously less per surprise.
- Mind the equity mechanics. Contractors and advisors cannot receive incentive stock options; they get NSOs, with different tax treatment. The details are in the ISO vs NSO guide, and advisor equity connects to how you structure the founding team's equity.
- The contract label does not decide classification; the IRS control test, the FLSA economic-reality test, and state ABC tests do, and the strictest applicable test wins.
- Federal enforcement softened in 2025, but the 2024 rule survives for private suits and state tests are unaffected. Build to the strictest standard you touch.
- Misclassification costs run in layers: taxes and penalties, wage claims, class actions, and diligence friction.
- Ownership is a separate trap: contractors keep their work product unless a written present-tense assignment says otherwise; employees need PIIAs from day one.
- Convert contractors to employees when the role becomes core; drift is where the liability accumulates.
The honest summary: contractors are a good tool used precisely, and an accumulating liability used by default. Decide each relationship deliberately, paper it accurately, and re-check as roles evolve. That is an hour of judgment against a quarter of cleanup, which is the trade this entire field of law keeps offering.
Related reading: who owns your startup's code, ISO vs NSO stock options, and the due diligence checklist. Or start a conversation about your team structure.