You still have to wait for the information to come from financial institutions before business taxes can be complete. You also have to make all entries and pretty much close the book except for year end entries on the business, too. Then most people have their small business taxes done by an accountant. Even if you give them a heads up, they have lots of returns to do. Mine has been good about it, but he is clearly doing me a favor. Only then do I have the information I need in order to do my personal return. I always made the deadlines, but it was close in years when my kids were applying. OP, I do think you dad COULD have had them done earlier IF he had really gotten his ducks in a row with his accountant ahead of time. But it is harder if you don’t start early and ask your accountant to do things early.