I place all material reciepts and a copy of all time cards in the job file for each and every different job. This makes it easier to determine profit or loss on a job. It also lets me more easily find any warrenty issue information. ( EG. had a customer want me warrent lights he had purchased 3 years ago. He "forgot he bought them".)
I keep the supply houses monthly bills in a supply house file along with the payment check noted on it.
This way is easier for me to find what I need.
