Form 990 is an information return that most organizations claiming federal tax-exempt status must file yearly with the IRS. Do not enter social security numbers on this form as it may be made public.Instructions: See Form 990 Thresholds to determine which form to file. Then see Current Form 990 Series for instructions. Form 990-N is easy to complete. You'll need only eight items of basic information about your organization. File the Annual Return Form 990. Note that the due date is 4 and a half months after the end of fiscal year. This Nonprofit Audit Guide provides links to the state laws that address audits so that you can determine what your state requires. Find 990 forms of private foundations, public charities, and other nonprofits.