• IRS Form 1040-X is filed by taxpayers to amend an annual tax return that was previously filed.

  • To receive a refund, the form must be filed within three years of filing the original return or within two years of paying tax, whichever is later.
  • Form 1040-X should be used to correct material changes, not to correct mathematical errors.
  • You can file the form electronically if you have filed the relevant tax return electronically. Otherwise, send it by mail.
  • You must include all outstanding and supporting documents on the form.