How detailed or itemized do my descriptions need to be for business expenses

[Fern]

You need to provide enough of a description so anyone reviewing the return can tell the category of expense. You do not have to provide so much detail that it is a huge project to enter in your expense information. The description that you provide must enable you to be able to produce supporting documentation if you are requested to produce it.

If you purchased 100 pens for business use, 50 black and 50 blue, you could enter it as 100 pens. If you bought 50 pens for office use that cost $1 each and 50 pens to give to customers that cost $10 each, you should report them separately.