I am going to help you out here as I am a master degreed accountant with a concentration in taxation.
If you have "earned income" in the US whether you physically exert labor or earn income passively through an investment, be it real estate or in your situation, virtual real estate. You need to report all income earned. Whether or not you receive a 1099 is going to be up the company. They should by IRS standards issue them, but not all companies operate correctly. Believe me, I have worked for many that had no clue what to do.
Here is what YOU DO NOT WANT TO HAPPEN: An audit. If you have under reported income in a prior year you will subject to large penalties and taxes.
I recommend doing this right from the start. If you earn more than $600 from an individual company (not all companies combined) then you need to report that as income. You do not need to own a business or be in business.
You would file this income as other income on schedule C. Here is where folks get misguided: I read where you ask about expenses and the company issuing you a 1099 not subtracting your expenses. Well think about that. They are not bookkeepers for us, respectively. It is our responsibility.
Schedule C has sections (many and varying) for deductions to income. You will begin with your gross income (total parking revenue). From there you keep up with all your annual, monthly, or one-time expenses in a spreadsheet and a copy of all receipts digital or otherwise.
Just plug them in as you pay them for backup if you are ever audited.
If you earn $700 a year from ABC Company and $200 from XYZ...only report ABC. You really should report it all, but you are not required too. Many contractors avoid taxation with this tactic.
If your expenses from parking from Company ABC are $200 for the year, then your reportable and taxable income from that venture is $500. Whereas
many make the huge mistake of paying taxes on the entire $700. The IRS is NOT going to ask you for your deductions or encourage you to write things off, so you need to be proactive as not to pay too many taxes.
Now, let's say you earn a large portion of your annual income working from your home office parking sites or doing other jobs that earn you income, i.e., content writer. You can now write of home office expenses taking the standard home office deduction (which is generous) or take actual expenses based upon the square footage of your home and the correlating dedicated home office square footage. Think of all the items it takes to run your home office. Electric bills, cable, internet, water, taxes on your home, rent, mortgage payment, and so forth. If your home office is 20% of the total square footage, then your 20% of those bills will be deductible. See which is larger, the standard or the actual home office expenses and you are allowed to take the larger.
By the time someone correctly writes off their expenses from income, the result is not so scary at all. Often it is close to null if you are not making much income. Plus, you got some great write-offs you could not utilize initially. And best of all, your mind and conscious are at ease for being above board and doing the right thing!
I hope this helps you in your understanding of passive income. Please be careful when talking to tax "experts." I have worked for the H&R Blocks of the world. These folks get a two-week training course and know enough to be very dangerous, misleading, and lack a true understanding of taxation. They know how to jump from one field to the other in a computer screen and how to ask appropriate tax situation questions.
They are good for those that could do just as good of a job as a high school grad filing their own taxes with a couple of W2s.
Past filing a simple tax return with a couple of W2s, I would get a real accountant with a degree (Bachelor's minimum) to do my taxes. Despite common opinion, they are just as cost effective (way less expensive usually), way more knowledgeable, and they can do the quick turnaround taxes directly deposited into your account just as fast as a chain. I say this not to bash the tax chains of the world but to alert people to what they can and cannot do. They have cost me way too much money and lost savings on taxes in the past before I knew better. It's like hiring a butcher to do a surgery. Very bad idea. He has a knife but knows nothing medical.
Good luck!