"I was paid in cash."

Why the cash doesn't matter

Labor Code § 3357: anyone rendering service for another is presumed to be an employee. The presumption does not ask how you were paid. It asks whether you were doing work for someone.

§ 3351 defines employee broadly and says nothing about payroll records, tax withholding, or a W-2. There is no provision anywhere in the Labor Code that conditions coverage on being on the books.

And an employer who paid you off the books almost certainly did not carry workers' compensation insurance for you either. That is § 3700, it is mandatory, and violating it is a crime. It also opens doors for you that a normal claim does not have. What happens when there's no insurance.

What being uninsured gives you

You can sue your employer in civil court. Labor Code § 3706 removes the exclusive-remedy bar when the employer failed to insure — which means pain and suffering, which workers' compensation does not pay.

And § 3708 hands you a presumption of negligence in that lawsuit, with the employer barred from arguing you were careless or assumed the risk. That is an unusually strong position.

Or you can proceed through the Uninsured Employers Benefits Trust Fund under § 3716, which pays benefits when the employer cannot. You have to join the employer properly for the Fund to be reachable, and that step gets missed. How UEBTF works.

Proving what you earned

This is the real problem, and it is solvable.

§ 4453(c)(4) lets earnings be determined by what will most reasonably represent your earning capacity, considering all circumstances. It is not limited to documents.

What works: your own testimony, bank deposits, a coworker's testimony about the rate, texts about pay or hours, photographs of you on the job with dates, customer records, the going rate for the work, and the employer's own statements to anyone.

And your employer is required by Labor Code § 1174 to keep payroll records for every person employed. If those records do not exist, that failure sits with them, and it is not evidence that you did not work there.