I have a small business in USA. For federal business taxes I need 6-7 documents. Then that process creates other documents I need for personal taxes, which also requires 6-8 more documents. So, I'm roughly 20 important documents per year for federal taxes. Nexus in 3 states, adds more. And save them all for 7 years.

The other end of the spectrum in USA is filling with the 1040-EZ which is like a 3-4 document process.