How to record your business expenses
You can generally deduct business expenses if you incur them for the sole purpose of producing income. If you claim expenses, you have to be able to back up your claim. You do this by keeping all your business related vouchers and receipts, and recording all your expenses in a journal, a computerized file, or a software accounting program.
The simplest method of recording these expenses is a basic sheet with columns that list the common categories of expenses. At the end of each month, total each column, and then start a new sheet for the next month.