First, never tell your CPA about cash income and then tell him/her you don't want to report it. Once it hits your CPAs desk, it is going in your tax return.
You pay tax on the NET, not the GROSS. So AG is a good tax write-off!!! As a detailing business, you can deduct all you supplies, auto expenses (if you travel), equipment, etc.
What you pay....
Social Security & Medicare Tax
This is about 12%. When you are an employee, your employer pays 1/2 and takes the other 1/2 out of your pay. When you are self-employed, you pay all of it.
Federal Income Tax
This will range from 10% to 35% depending on how much you make. $9,000 to $35,000 you pay 15% if that gives you an idea.
State Income Tax
For Pennsylvania, figure about 3%
Add these up and you will pay about 30%. As your income exceeds $35,000, your rate will climb up to about 40%. Add to that business license and property taxes. If you hire employees, you have employment taxes in addition.
The key to tax savings for you is DETAILED EXPENSE RECORDS!!!! Set up a seperate bank account just for your business. Keep track of everything you spend related to your business. Remember, everything you buy on AG (or elsewhere), really you are paying 70% of it and the government is paying 30%.
Good luck!
By the way, I am a CPA and prepare taxes for a living. Detailing my own cars is just a hobby.