I inherited a client that sold a business several years ago in an installment sale. For simplicity, let's say he reports $100,000 each year in installment sale income on Form 6252. Each year he also sends 1099s to several other people, each for 2% of the annual income he reports from the sale (so $2k each). 

I don't see the 1099 payments reported anywhere on his previous tax returns and I am wondering if those are deductible at all? I don't have the original sale agreement so I don't know anything else about the substance of the payments. The client hasn't said anything, I'm mostly just curious.

Could someone point me in the right direction as to whether those payments are deductible and/or how they would be reported on the tax return?