The first question is whether you would be considered an employee or an independent contractor. This depends on your relationship with the main contractor or employer. If you worked occasional jobs, and you had the freedom to decide not to help out on a job if you were doing other things that day, you were probably an independent contractor. If you were required to show up at specific times, work a regular schedule, using tools and equipment provided by the employer, then you may be an employee.
If you are an independent contractor, then you report self-employment income on schedule C. Although your prime contractor would be required to issue a 1099-NEC form if they paid you more than $600, you are also expected to keep accurate business records of your income and expenses and report and pay taxes even if you don’t get a 1099. You need to set up the job in TurboTax, and then you can enter “other cash income“ not reported on a 1099. You can also deduct expenses that you paid in order to earn money to do this job. That might be tools that you purchased yourself, or mileage driving to different jobs. If audited, you would need to have accurate records of your expenses, so it may not be worth the risk to just guess at your tools or your mileage if you did not keep records. Your net business income after expenses is subject to income tax and self-employment tax.
if you believe you were an employee, then your employer was responsible for issuing a W-2 and withholding certain taxes on your behalf. To file as an employee, you would create a substitute W-2 in TurboTax. You must also fill out and submit a form SS-8, which is a request for a determination of your employment status. You will describe the job, how you did your work, and your relationship with your employer, and the IRS will make a determination if you were an employee or a contractor. If the IRS determines you were an employee, your employer will face certain penalties. If the IRS determines that you were an independent contractor, they will adjust your tax return to reflect that situation, and you will probably owe an additional tax payment.
