All businesses—whether or not they have employees—can use expense reports to keep track of write-offs for annual tax filing. These can be the same as expenses employees may report (and will include any reimbursements made to employees), but will also include larger scale business expenses such as rent, utilities, insurance, equipment, and other business purchases.
Regardless of the size of your business, an expense report is a great way to track and summarize business expenses. This can help you better understand where your money is going to help you cut costs or adjust how you allocate your funds.