Not really. The IRS really does know your W2 and all your bank and investment income. If you've worked for several different companies, you often have scattered investments that you have to chase down that, in fact, they already know. There's really no reason why they couldn't provide you with pre-filled forms for all that stuff. Sure, there's stuff they don't and can't know, but for most people those are the simple things (how many children, marital status.