As soon as you go in to business for your self, you have a partner… the IRS. They expect to know exactly where every single penny of revenue and expenses was spent and they want to see proof.
It’s none of their damn business as far as I’m concerned but there is no way to avoid it.
If you pay anyone any money, they want to know who you paid, how much and why. You have to send in proof every year and it needs to be tied to the person’s social security number. Sure you can pay under the table. But then there would be a break in the paper trail which could raise a red flag and cause YOU to be audited.
The easiest way to handle payments to your bird dog are to give them an option on the property that they will be paid $X for the referral. They that paperwork in to the title company along with the purchase contract. It will show up as a line item on the HUD-1. They title company will issue them a check or wire $ to their account.