I am a W-2 employee but have a side gig related to real estate investment. I do not have a LLC or DBA. Last year I incurred related expenses such as marketing costs, mail box rental, mileage, and professional membership fees. Can I deduct any of these expenses without related income this year? Someone told me to keep tracking the expenses and carry them into the next year when I do make money from this. Are there any other options to handle these expenses?
No. The advice was sound. All of your start up expenses go into one big bucket until you begin making money. Once you start making money with your business, you write off some off your start up costs (up to $5,000) and amortize any remainder. If you go over $50,000, there are different rules but you should not reach that point. The SBA has a great section, Calculate your startup costs.
Notice in How does starting a business affect my taxes? that expenses reduce your taxable income.
Once you start making money, you will have to pay the Self-employment tax and need to make quarterly Estimated taxes or increase your withholding with your job.
Reference: Small Business and Self-Employed Tax Center | IRS