Is there a way to automatically generate an expense transaction from an invoice line (ie when monies are received 20% has to be paid back out)? Can that be automated?

Hello richards343, Welcome to the Community post, there is no way to automatically generate this in Quickbooks, you would need to enter this manually into your account.  You would need to record the money coming in via an invoice with the total amount on it along with the 20% and then record the money going out via an expense with 75% on it. We would advise that you speak and confirm with an accountant if this is the best way to record it in your account as they may advise a different way for you to enter it into your account.