Thanks for your reply - 

We run a racehorse service business and usually dont deal with the shareholders , but now we are accepting more direct client billing (shareholders) 

Another question I have is , 

A work around is to create an invoice and then discount it by the relevant percentage of share holding to arrive at the correct % of the total bill - but i have to create the same invoice multiple times (possibly up to 12) , what effect will this have on my accounts ? will we see inflated sales values on the dashboard  or will the discounted amounts be taken into account ? 

I know when we run a sales report , it shows the discounted amounts separately