Form W-9 doesn't have a due date. However, most 1099 forms are due at the end of January, so it's important to have a payee fill out a W-9 before you submit your 1099s. Plan accordingly to allow your payee enough time to provide their information. Businesses can prevent delays and improve efficiency by having an independent contractor or another self-employed individual fill out a W-9 before they begin completing work for the company.