What this letter is about Call us so we can verify your identity and process your federal income tax return. What you need to do If you didn't file: Call us immediately to confirm that you may be a victim of tax-related identity theft. If you filed: Call the IRS Identity Verification number on your letter. Have the following available when you call: The 4883C letter The income tax return referenced in the letter (Form 1040, 1040-A, 1040-EZ, 1040-PR, 1040-NR, 1040-SR, etc.). Note: A Form W-2 or Form 1099 is not a tax return. A previous year’s income tax return, other than the year in the letter (Form 1040, 1040-A, 1040-EZ, 1040-PR, 1040-NR, 1040-SR, etc.). Note: A Form W-2 or Form 1099 is not a tax return. Supporting documents that you filed with each year’s income tax return (Form W-2 or Form 1099, Schedules C or F, etc.). If we can't verify your identity over the phone, we may ask you to schedule an appointment at your local IRS office to verify in person. If we don't hear from you We may not be able to process your return, issue refunds, or apply overpayments to next year’s estimated tax. The toll-free IRS Identity Verification number is for identity verification only. No other tax-related information, including refund status, is available. You can find more information in Publication 5027, Identity Theft Information for Taxpayers PDF. Frequently asked questions What happens after I call? Once we verify your identity and confirm you submitted the tax return, we’ll continue processing your return. It will take approximately nine weeks to process. Reference Tools Publication 1, Your Rights as a Taxpayer Publication 17, Your Federal Income Tax Full list of tax forms and instructions Need Help? See if you qualify for help from a Low Income Taxpayer Clinic. If you can’t find what you need online, call the IRS number at the top of your notice or letter.