Yes, you can file your tax return but you can't claim business expenses if you don't have receipts or some other kind of proof. If you have some of the receipts, or you have some other proof of the expenses, you can enter them on your Schedule C, Profit or Loss From Business. Here's how to deduct work-related expenses.
Note: Schedule C's are the most common forms that the IRS audits so make sure anything you enter, you can prove.
