Worker Classification: The ABC Test, IRS 20-Factor Test, and Misclassification Penalties

Getting worker classification wrong is expensive. When the IRS or a state agency determines that workers classified as independent contractors should have been employees, the business owes back employment taxes (the employer’s share of Social Security and Medicare, plus FUTA), penalties for failing to file W-2s and withhold income tax, interest on the underpayments, and potentially retroactive liability for benefits the workers should have received (workers’ compensation, unemployment insurance, health insurance, retirement plan contributions). The IRS uses a facts-and-circumstances test derived from common-law principles, often summarized as the 20-factor test (Revenue Ruling 87-41), which examines behavioral control (does the business direct how, when, and where the work is done?), financial control (does the worker have a significant investment, unreimbursed expenses, or opportunity for profit or loss?), and the type of relationship (is there a written contract, benefits, permanency?). Some states, including California, have adopted the stricter ABC test, which presumes every worker is an employee unless all three conditions are met: the worker is (A) free from control and direction, (B) performs work outside the usual course of the hiring entity’s business, and (C) is customarily engaged in an independently established trade, occupation, or business.

What happens when workers are misclassified?

Does IRS relief after reclassification cover a state ABC claim?

No. Section 530 and the IRS settlement program are federal. At the start of a classification audit the IRS has to give written notice of Section 530 and consider it first, and if you qualify it relieves the business of federal FICA, FUTA and income tax withholding plus related interest and penalties. A state applying its ABC test decides on its own.

Section 530 needs all three of these: every required 1099 filed consistently with contractor treatment, no worker in a similar role treated as an employee, and a reasonable basis.

If you’re not under audit, the Voluntary Classification Settlement Program lets you move workers to payroll going forward. You pay 10% of the employment tax liability on their most recent year’s pay, figured under the reduced 3509(a) rates, with no interest or penalties on it. You can’t use it while a DOL or state agency is auditing your worker classification, or during an IRS employment tax audit. The IRS says it won’t share VCSP applications with state agencies, which isn’t the same as the state agreeing to anything.

What records hold up under both the IRS test and the ABC test?

Keep proof of how the work really runs, since both tests look past the contract. The IRS weighs all the evidence of control and independence, and California’s ABC test asks whether the worker is free from control both under the contract and in fact. A signed agreement only helps when the day-to-day facts match it.

• A 1099-NEC filed by January 31 for each worker you paid at least $600 in 2025 or $2,000 in 2026. For Section 530, a 1099 filed after the IRS first contacts you about an exam doesn’t count.
• Evidence of an independent business: the worker’s own tools and investment, unreimbursed expenses, other clients, and a real chance of profit or loss. The same facts speak to the ABC test’s third prong.
• A note made at the time of what you relied on, such as a court case or ruling, a past employment tax audit of similar workers, or advice from a lawyer or accountant who knew your facts.

No record fixes prong B, though. In California, work inside the usual course of your business fails the ABC test however well it’s documented.

• Worker Classification: Independent Contractor vs. Employee, the 20-Factor Test, and IRC 530 Safe Harbor Protection

What does misclassification cost under state ABC and IRS rules?

The costs run on separate tracks, because each agency uses its own test. Federal tax status is decided under the IRS common-law rules, and that bill is the employer’s 7.65% FICA, FUTA, and the withholding and employee FICA that weren’t collected, which IRC 3509 can figure at reduced rates. A state using the ABC test, like California, reaches its own answer and adds its own penalties.

California presumes a worker is an employee unless the business proves all three ABC prongs. If the misclassification is willful, Labor Code 226.8 adds a civil penalty of $5,000 to $15,000 per violation, or $10,000 to $25,000 per violation for a pattern or practice.

Wage-and-hour law is a third track. The DOL tests status by economic reality, so a worker can come out one way for tax and another for overtime. On the federal tax side, the 6.2% Social Security part of FICA stops at the wage base ($176,100 for 2025, $184,500 for 2026), while the 1.45% Medicare part has no cap.

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.