If I have access to a big hall/room in a building I own and I wanted to convert it into a personal gym. Then one day I say to a friend, you can use my gym if you give me $100 a year, and I will give you $10 back for each person you get to join my gym who will pay $100 a year.
Do I need to start a company to do this? Will I have to pay tax on the money I receive from the possible friends? Will my friend have to pay tax on the $10 he receives for every person he introduces to my personal gym?
I have the same opportunity in the United States and in the United Kingdom.