Information For...

For you and your family
Standard mileage and other information

Forms and Instructions

Individual Tax Return
Instructions for Form 1040
Request for Taxpayer Identification Number (TIN) and Certification
Request for Transcript of Tax Return


Employee's Withholding Allowance Certificate
Employer's Quarterly Federal Tax Return
Employers engaged in a trade or business who pay compensation
Installment Agreement Request

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Amend/Fix Return
Apply for Power of Attorney
Apply for an ITIN
Rules Governing Practice before IRS

Understanding Your 4883C Letter

We received your federal income tax return, but we need more information to verify your identity in order to process your tax return accurately. The contact information below is only for taxpayers who received Letter 4883C.

What you need to do

  • Call the toll-free IRS Identity Verification telephone number at 800-830-5084.
  • When you call, you must have:
    • This letter
    • A prior year tax return
    • The tax return for the year the notice is for
    • Any supporting documents for each year’s return, such as Forms W-2 or 1099, Schedules C or F, etc.

The toll-free IRS Identity Verification telephone number is available for you to call even if you haven't filed a tax return for this year. However, we can’t discuss any other tax related information during the call.

Answers to common questions

What happens after I call?

We’ll continue processing your tax return once we verify your identity and confirm that you submitted the return. If you did file the return, please know it will take approximately nine weeks to process it once you verify your identity.